Cassie Sullivan

"I am the one not running, not staying, but facing. Because if I am the last one, then I am humanity. And if this is humanity's last war, then I am the battlefield."

- Cassie Sullivan

Cassiopeia Marie "Cassie" Sullivan is the main character of The 5th Wave trilogy by Rick Yancey. She was a survivor of the 'waves' sent down by the Others to wipe out humanity. Her younger brother is the only other surviving member of their family as she has lost both of her parents to the waves.

Cassie has joined together with Squad 53 and travels alongside them as they try to fight against The 5th Wave that has just been started by The Others to eliminate what is left of humanity. Cassie has had a strong and consistent hatred for the Others since they started launching the waves that has since been challenged since she had met and developed feelings for the silencer Evan Walker.

Cassie ultimately sacrifices her life to destroy The Others' spaceship and thus saving the remaining number of humans on Earth. Her brother is left in the care of Ben and Ringer, plus Evan (for a time). Ringer has a daughter that she decides to name Cassie in her honor.

Cassie serves as a narrator in all three books.

She is portrayed by  Chloë Grace Moretz  in the film.

Physical Appearance
Cassie is described as having strawberry blonde curls. She also says that she's short (she is only a little bit taller than 1.60m [5,3] ) and her build "isn't big."

Etymology
Cassie was given her name by her father on account of a field trip he took to a planetarium he took as a kid. He saw the constellation Cassiopeia and became drawn to it and so named his daughter after it fifteen years later.

The 5th Wave
Cassie, at the beginning of the story, is on her own in the woods with her rifle going on a supply run. She goes into an abandoned store for supplies when she runs into an injured but armed man. He asks her for her help but she remains on guard and keeps her weapon on him. She isn't sure that he was human or a Silencer and opens fire on him when he pulled out his hidden hand. She thought it might be a gun but is horrified to see that it was a crucifix. She carries the horror of this time with her for much of the book. She then begins to write in her journal for whoever may come to read it and even makes comments about her thoughts on The Others should one of them stumble on it so that they know what she thinks of them.

When The Others first showed up Cassie wasn't sure what to think of them, she lost herself in what other people had thought of them. She tried to go about her life as normal with going to school, hanging out with her friend Lizbeth and admiring Ben Parish from afar. She went on a date with a new boy named Mitchell but they didn't have a good time. On the morning of the 1st wave, 10 days after the Arrival, the power suddenly went out. There was confusion that was quickly followed by fear as there were loud sounds being heard from the outside.

Cassie and the rest of her class watched as a plane started to fall from the sky and crashed not far from their window.

Everyone at school gathered at the gym and Cassie caught a glimpse of the back of Ben's head and Lizbeth tried to convince her to tell him how she feels to which she refuses. When her father came to pick her up from the school she said goodbye to Lizbeth with a promise to call when the power came back unaware that this was the last time they will see each other. She and her father hiked back to their home and saw how the wave made a mess on the roads and caused many to be hurt. Later on, news arrived from passerbys that giant tsunami waves had flooded the east coast and buried cities underwater as the 2nd Wave.

When the 3rd Wave hit Cassie's mother became ill and when she died her father buried her in their backyard. Her father then decided to leave their house to head for Wright-Patterson as he felt they would be better off there. He felt that if there was any semblance of government and safety then it would be at that base while the cities were starting to plunge further into chaos. On their way there they stumbled onto Camp Ashpit. With it being somewhat safe and secure they decided to stay there. While there, Cassie became the interest of a younger boy called Crisco who tried to hunt things in their corpse pit that she might like. A few days later, the people in the camp spotted what seemed to be drones flying through the sky and they knew that they couldn't be any of theirs so it had to belong to the Others. Her father guessed that they were testing the conditions on the Earth for them to finally arrive.

While still wondering what to do, a chopper was spotted flying overhead and the people of the camp tried to get its attention. They were surprised to see that their seemed to be some power returned to them after the 1st wave and soon Humvees and school buses pulled up close to the camp with soldiers in gas masks led by colonel Vosch. Cassie's father went with some of the other camp leaders to investigate and they learned that they were from Wright-Patterson and had been in intensive quarantine but now were out. They requested for the children to be loaded in the buses as they would be taken to safety first. Cassie saw Sammy off and he left his Bear to her for her to give back to him when they saw each other again. Vosch requested for everyone to gather together but Cassie noticed that Crisco was missing. Her father insisted that she go and find him and Vosch had two men go with her. When Crisco was found, he was promptly killed by them and Cassie dodged them and tried to head back to the camp in time to see her father get shot and killed by Vosch. It was then she realized that the 4th Wave had been unleashed as The Others walking among them looking like humans.

She had gone into hiding into the wilderness ever since then and kept herself in isolation until it seemed that she could be the last human left. Cassie then started to survive out in the wildnerness on her own. She was careful to keep herself isolated as not to run into silencers. She stayed in walking distance from a fill-up station to be in range of supplies until the crucifix soldier incident. She then realized that she couldn't stay around there anymore and started to head on out but was still careful to avoid people or drones. She kept to the wilderness close by the highway but avoided going near any of the cities. She found a nice and out of the way spot in the woods where there was a fill up station nearby where she would frequently go for water and supplies but then left the area after she ran into that soldier with the crucifix.



She was on the highway when she came upon a family of three, or rather their fresh bodies. She saw that they had been shot and soon she was being shot at. She was shot in the leg and then went, struggling, to hide under a van. She knew that she would either be shot or bleed to death and tried to run but the pain and blood loss kept her from going too far. She regained consciousness to find that she had been brought to a farmhouse belonging to a young man named Evan Walker.



Her wounds were being treated but she wasn't fit to travel on her own and would need to be under care for a while so she couldn't get to Wright-Patterson as fast as she wanted. Cassie was mistrustful of Evan at the beginning but little by little she began to warm up to him. She learned that all of Evan's family had been lost due to the plague of the 3rd Wave some time ago. Cassie was talking to Evan one night when he let it slip that he had read her journal. She got into a fight with him which led him to confess feelings for her as well as kiss her, and her to allow him to go with her to Wright-Patterson.

Over the next few days Evan and Cassie trained and prepared for their trip. Over this time however, Cassie grew suspicious of Evan, thinking he had hands to soft for a farm boy, as well as smelling gunpowder on them. The next day she found her gun in his barn when he had been on one of his hunting trips. While she was still in the barn, he caught her. She tried to cover it up, claiming she heard rats, but Evan seemed to know the truth. Cassie was still suspicious of Evan a little bit, but let it go for the time being.

As they were getting ready to leave, Evan set fire to his farmhouse to cover their tracks. They neared the base, they ran into some young soldiers and Evan quickly disposed of them by himself. With seeing how he handled those soldiers single-handedly, she turned her gun on him as she deduced that he must be an Other. Not just any Other but the one that had shot her. She also realized that the hunting trips that Evan had gone on were really times when he would hunt and kill other people that he found like herself. Evan quickly said that he was neither Other nor Human. He was both and he was the one that had shot her in the first place. Cassie refused to listen to him until he informed her that Camp Haven wasn't a base, it was a death camp. He explained about the 5th Wave and that her brother was most likely being trained to be a soldier as well for it. He also gave her insight on the Arrival and the Waves from the Others' point of view. He told her that she wouldn't be able to infiltrate the Camp and save her brother without his help, which she grudgingly had to accept.

She got detailed information on the Camp and its operations from Evan and then preceded with the plan. She first let herself get picked up by one of the buses transporting fresh kids to the Camp. She was then put through the process where she met with one of the doctors. She quickly then knocked the doctor out and then removed the tracker she had been freshly tagged with and put it into the doctor's own nose so that the doctor would kill themself instead of her when they activated the kill switch. She tried to hack into the system and find her brother but couldn't do it. So, she incapacitated another soldier and stole his uniform to move through the base. By that time, Evan had been sniping at soldiers at the guard towers and alarms were being sounded. She learned that the younger children were being brought to the bunkers below and made her way there.

Once there, she went through the sea of young faces until she found Sammy. She quickly gave him back his bear but he ignored it to hug his sister. He thought she was a new soldier but she told him that they were leaving. They tried to leave the base as inconspicuously as they could when they crossed paths with what seemed to be a doctor with a facemask. One that noticed them and seemed to be going for them. Cassie had flashbacks of her time with the Crucifix Soldier and pulled her gun out just as the orderly pulled out his own. But before she could shoot him or he shoot her, her brother jumped in front of her and went to pull his mask away revealing that it was Ben Parish or Zombie as he was now called. She was surprised to see that Ben was still alive as she had long ago resigned to the fact that he was dead. Also, she was surprised to see that he apparently was very familiar with her brother and seemed to be looking for Sam to escape with him as well. Sam smoothed over any suspicions that Ben had with her and then suggested that they all leave together. They both agreed.

Before they could go however, Cassie remembered that Sam still had his tracker and it had to be taken out. She pulled out a combat knife but Ben pulled out a scalpel which Cassie was grateful for. Ben then went to cut Sam's tracker out of him but before they could begin to escape they had run into Vosch who was waiting for them. Vosch took Sam away and put him into the execution room's chair while he detained Cassie and Ben. Vosch explained that the Others had been watching humanity for thousands of years. To try and protect Sam, she had offered to be plugged into Wonderland but Ben tried to stop her by saying that Vosch would kill them all anyway. When Vosch went to execute Sam, the system had already been shut down, by Evan. Vosch went to see to it leaving two silencers there to watch them but Cassie quickly moved to incapacitate them. Evan then came upon them and told them the way out. He told Cassie that she was right and he had to choose and he chose humanity. He promised that he would find her again and left to see that the base was destroyed for good.

Cassie, Sam and Ben then left for the collapsed stairway and climbed it to try and break for the surface. It was hindered due to Ben's gunshot wound but they managed to get out just as the last flying transport took off with the camp's personnel. The ground started to collapse and the three of them were forced to make a run for it. A humvee soon came upon them which was occupied by Squad 53 and Ringer told them to get in. Ben helped Sam in but Cassie lost her footing and nearly fell down into the building chasm. Ben then went and pulled her to safety and threw her into the humvee and they drove off as the base finished collapsing. After they were a safe distance away, Cassie then met the rest of the squad, including Ringer who she seemed irked by. She, Sam and Ben were all then treated by Dumbo and bandaged up from the cuts and scrapes they suffered in their escape. Cassie then sat with Sam and Ben, who gave her a thank you kiss, before they watched the sunrise.

The Infinite Sea
When Camp Haven was destroyed, Cassie told Squad 53 of a fallback spot that Evan told her to meet him at after they escaped. It was an abandoned hotel and Ringer had taken the liberty of christening it 'The Walker Hotel' for the occasion which Cassie was a little annoyed about. Cassie had filled in the squad of what she had learned from Evan about the Others and a few of them were skeptical about her explanations, chief among them Ringer. As they hold up in the hotel Cassie and Ringer find it harder to get along. They argue and have even come close to getting into a straight up fight but it was stopped by Ben Parish, who had become somewhat of a mediator between the two.

Cassie finds that her brother Sam is different from how he used to be. She is surprised that he abandons his bear almost at every turn when he used to keep with him everywhere. He insists that he doesn't need it anymore and tells her that if she wants it then she could have it. He also seems to know what had happened to their father and he seems quite mad about it with her. Sam begins to lash out at both her and at Teacup, who insulted him about it, until Ben forces him to calm down. When he does, Sam asks Cassie to tell her how exactly their father died. She tells him that Vosch killed him and spins a story of their father fighting hard against Vosch and his men before he was taken down. Sam vows to find Vosch and kill him but Cassie tells Sam that she has already called dibs on it.

The hotel soon begins to be a poor shelter against the drop in temperatures, as it is now coming into winter. The popular idea is to leave and find a much better place for them to hold out. Cassie insisted to the squad that they should stay at the hotel just in case Evan comes here looking for them but they all believe that he is dead. Ringer volunteers to scout the nearby cave systems to see if they are suitable and if there is any sign of human life to help them fight against the 5th Wave.

When Ringer left, the others were trying to decide on what moves to take after as well as what to do if Ringer found that the caves weren't suitable. Ben preferred to find some way of getting south but the others didn't think it was wise as it was too far for them to go. An issue came up when Cassie referred to her brother as Sam while Ben referred to him as Nugget. She felt that her brother should choose one name as not to let it be confusing. It was decided that he stick with Sam. Soon after, they realized that Teacup was missing. They realized that she must've gone after Ringer and Ben sent Poundcake to go and bring her back. However, as they waited, the hotel was besieged. The squad was taken down one by one. Cassie managed to get the jump on the assailant and shot him in the leg. They then saw that it was Evan Walker.

Cassie asked him what happened to him but all Evan managed to say was Grace and Cassie believed that he was trying to pray. Evan is taken and put into a room to try and recuperate while Cassie and the squad think on what to do. Tensions ran high when there was the sounds of choppers heard nearby, on and off. Ben believes that Evan might've attacked Ringer and Teacup on the road but Cassie defends him. Ben tries to remind her that he is a Silencer and this could all be a trap, but she counters that Poundcake could be guilty as he had returned without either of them and never speaks so he could be a literal Silencer. They trade theories, and shouts, and it seemed that there might be a split between staying at the hotel with Cassie and Evan or leaving with Ben.

The debate was interrupted with the arrival of Megan. Sam immediately recognized her as the girl he met on the buses when he was heading to Camp Haven. They wondered what she was doing there especially given that she wasn't dressed for the cold weather. Cassie was a bit suspicious of the girl even though she was roughly her brother's age. Yet Evan managed to wake up and told them to not crowd the girl. He informed them that she had a special explosive chip inserted in her throat that would detonate when it was surrounded by enough carbon dioxide. Evan told them that he knew what needed to be done to remove the bomb from her. Ben felt that it would be safer to kill her first as it would lessen the chance of the bomb exploding and killing them all. Cassie argued that they should try to take it out and save her life. It seemed that Ben just decided to do it as he felt that there really was no other choice. Cassie went to him afterwards to tell him that there was a choice. She then realized that Ben didn't kill Megan after all and chose to try and get the bomb removed with her still alive.

Cassie chose to stay behind with Evan so that they could work together and remove the bomb. Ben was to take everyone else out of the hotel to a diner across the street for safety. Ben and Cassie had a moment to themselves where he told her that the Others made a mistake in not killing her first. Cassie gave Ben a peck on the cheek and Ben responded by giving her a real kiss. Cassie then went and helped Evan remove the bomb, which was a very tense experience. But, in the end, they succeeded and got the bomb out of Megan's throat sparing her life. However, Evan confided in them that Megan was most likely sent as a test. Not for them, but for himself, to see if Squad 53 had a Silencer on their side like Vosch suspected back at Camp Haven.

To throw off Vosch, Evan made a plan to rig the explosion with CO2 from a soda dispenser from the diner across the street of the hotel. Ben and Poundcake volunteered to get it. Soon after they left, the hotel was attacked again and Evan realized that it was Grace who must've followed him. Grace managed to corner both Cassie and Dumbo and moved them so that they all were in the room with Evan. Cassie was worried for her brother and Grace played around with the fact that she might've hurt him. When Grace realized that Cassie was the human that Evan had been taken with, she mocked her and went to deeply kiss Evan in front of her. Soon though, Ben and Poundcake managed to come back and they helped drive Grace to run off and regroup.

After Grace retreated, they saw that Poundcake had been fatally shot by her. Soon, a chopper started to descend on the top of the hotel. They realized that they couldn't stay there and Evan told Cassie to take everyone and go to Grace's safe house where they would be safe and supplied. He told her of a pod that would descend there soon and to take it and 'end this'. He would stay behind and rig the Megan's bomb to eliminate the Silencers and Grace. They all ran out of the hotel but Ben was hindered by his efforts to get Poundcake out of there. Dumbo told Ben that it was too late for him and Cassie watched as Ben had to regretfully set his friend down and continue on without him. They were a safe distance away when the hotel exploded in a flash of green light.

They were off in the wilderness outside the city. Cassie watched as Sam and Megan slept, Dumbo kept watch, and Ben quietly mourned for his friend Poundcake. They were all put on alert when something was heard coming closer. They looked to see that it was Evan, wounded but still alive.

The Last Star
At the beginning of The Last Star, Cassie Sullivan is taking refuge in Grace's old house with the remaining members of Squad 53, Evan Walker and Megan. While in the safe house, Cassie attempts to engage Evan Walker in a romantic display of affection. Evan refuses after he and Cassie fight, and Cassie questions where Evan's loyalty lies.

Ben begins to worry about Ringer and he volunteers to head back for the city to look for her. Dumbo also volunteers to go. Cassie tries to talk Ben out of this as there is a chance that Ringer might be dead and he was heading out to die. However, Ben insists that he has to go. When he leaves, Cassie tries to connect with Sam but he becomes closed off from her with Ben gone. She begins to worry about Sam as he claims that he doesn't even remember what their mother looked like before she became sick. Not only that but she also discovers that he doesn't know his ABC's anymore and watches as he quickly and expertly knows how to put together and make a homemade bomb.

After Ben and Dumbo head out of Grace's safehouse to find Ringer and Teacup, Cassie continues to voice her concern for Sam, as he had forgotten his ABC's and his mother's face before she succumbed to the 3rd Wave, but was competent in the handling of firearms and making of bombs. Later, Ben had returned to the house with Ringer and a newcomer by the name of Constance. Dumbo had been killed back in the city by a Silencer.

Sam Sullivan
Sam Sullivan is Cassie's younger brother. Despite their eleven-year age gap, the two are incredibly close. Cassie becomes the most prominent caretaker in his life after the death of their mother, washing his hair and helping him say his prayers each night. Cassie affectionately calls him "Sams".

When they are reunited, Cassie starts to see that Sam isn't the same timid little boy that she remembered. He has become harder and hostile. He keeps insisting to her that he's a soldier now and also rejects his bear which she has started to keep close by herself. She is also surprised to see how much Sam seems to follow after Ben and how loyal he seems to be to him. Perhaps even more than he is to her.

As they regrouped at Grace's safehouse, Cassie was even more shocked and disturbed that Sam was starting to forget how their parents looked like as well as the good memories of their lives before the waves. She even saw that Sam was not even able to remember the alphabet but knew how to assemble homemade bombs quickly and masterfully. However, he surprised her when he told her that he remembered their mother when he had shot a Silencer that was holding him hostage. When she was leaving to try and rescue Evan from Vosch, she embraced Sam and shared a final memory with him, from when he was a small child of playing with him using a hose in the bright sunlight to make him 'chase rainbows'. She then left him in Ben's care and hoped that he would take care of him and help him become more than the brutal soldier that he was shaping himself into.

A year after her death, Sam confides in Ben that he deeply misses Cassie.

Oliver Sullivan
Oliver Sullivan is Cassie's father. He is a very caring, upbeat, and positive father to Cassie and Sammy and works hard to keep them alive during the Waves. She has memories of him giving her a telescope and teasing her lightly before the Waves hit. Cassie's love for reading might have been influenced by her dad, who also had a "thing" for books. He starts collecting all he can before the 3rd Wave for the purpose of "rebuilding aspects of civilization." Her last memory of him was him crawling on the ground and mouthing for her to stay hidden before he was shot in the head by Colonel Vosch.

She was able to avenge his death when she went and shot Vosch in the head just like he had done to her father.

Evan Walker
Evan Walker is Cassie's main love interest in the first book. He is a Silencer who found and shot her duting one of his hunting rounds but found that he was unable to kill her. He takes her to his home, a farmhouse, and nurses her back to health. The two become close during that time, and Evan expresses romantic and protective feelings towards Cassie, though she is still distrustful of him. At one point, the two kiss deeply and fall asleep together. He is intent on helping Cassie find Sammy again, even offering to go by himself to keep her out of danger. The two end up leaving together to find Sammy, after Evan burns down the Walkers' farmhouse.

Cassie confirms that he is the Silencer who shot her after he takes down four soldiers by himself. Evan, however, is very injured in the process, and she removes the shrapnel while questioning him. He gives her insights about the invasion from his alien point of view and even shows her his "state of being" by entering her mind. When Cassie heads into Camp Haven alone, he protects her from afar by sniping at enemy "infesteds". When the two are reunited, she runs into his arms and is overjoyed to see him again, and he strokes her hair, and calls her by his special nickname for her: "Mayfly", another way of saying I love you. He then goes back to level the base, promising her that he'll find her again.

In The Infinite Sea we see Cassie and Evan's relationship put to the test. When the two of them meet again Cassie went and shot him in the knee as "payback". She then quickly forgives him and they share a 'reunion' kiss which the squad sees. Cassie tries to defend Evan against the accusations of Ben on whether he really is there to help them or kill them. When Grace, another silencer that personally knows Evan, attacks the hotel Evan and Cassie are separated once again. They are forced to say goodbye again and share another kiss. In the chaos of the attack the hotel is blown up with Poundcake, Grace and Evan still inside. At first, it is believed that none of them survived. At the end of book it is seen that Evan has survived as he limps out of the brush and is reunited with Cassie as well as the rest of the squad.

Ben Parish
Ben Parish is Cassie's childhood crush and her affection for him hasn't left her even in the midst of the The Others. Ben and Cassie went to the same high school and rode the same bus in middle school. While the two hardly ever came in contact, Cassie developed an infatuation for him. She found his smile to be his most handsome and appealing feature. Cassie's friend Lizbeth often tried to convince her to act on her feelings for Ben though she always hesitated and never did. When the first wave hit, Cassie saw the back of his head in a crowd at school and for the longest time, she assumed that was the last time she would ever see of him.

When Cassie was alone in the woods, she often pulled out his yearbook picture and thought about him often. The logical part of her mind accepted that Ben was dead she kept him alive in her mind's eye. She was shocked to see him again at Camp Haven (skinnier and paler than she remembers), and even more shocked to see his close friendship with Sam. Even though they were in a tense situation with them pointing guns at each other, she felt self conscious about how she was looking with him. When he asks her to trust him, she notes that she probably wouldn't have if he had been anyone else. They help to save both Sam and each other during their escape from Camp Haven. At the end of the The 5th Wave Ben kisses her on the cheek and put his arm around her while she has her arms around her brother as they watch the sunrise.

In The Infinite Sea, it is seen that Ben has started to put more emotional trust in Cassie. He reveals to her his feelings about Vosch and how the man gave him hope when he had none and Cassie laments that Vosch must've wanted for Ben to learn the truth as a way to break him. Ben and Cassie also tend to argue about the issue of Evan Walker and whether they can trust him or not frequently. Even more when he finds his way back to them. When they were found by a little girl who happened to be one of Vosch's child bombs Ben argued that they should kill her as it would be the safest way to remove her bomb without it exploding and kill them while Cassie argued to try to remove it while she was alive. Ben was adamant about following through with his way and went to just kill her and get it over with. Cassie was angry with Ben the next moment she saw him until she saw that he couldn't bring himself to kill her. When Ben went to move everyone else but her and Evan to safety she kissed him on the cheek and then Ben gave her a genuine kiss. She also tends to empathize for him when he is forced to acknowledge that his friend Poundcake is dead when they are evacuating the hotel just before it blows.

Lizbeth Morgan
Lizbeth was Cassie's best friend growing up. They would hang out and talk about what other teenagers typically did. Lizbeth knew of Cassie's long time crush on Ben Parish and often would try to convince her to 'go for it' and try to ask him out though Cassie would always shoot her attempts down. When the waves started, the two of them tried to keep everything normal around them as much as possible. When Cassie went on a date with the new boy Mitchell and was having a bad time, she called Lizbeth and begged her to 'save her'. After the First Wave hit, Lizbeth met Cassie in the gym and tried to convince her to try and tell Ben how she felt about him one last time. When her father picked her up, Cassie and Lizbeth shared one last hug along with a promise to call each other when the power came back which never happened. That was the last time they ever saw each other. Cassie kept a photo of Lizbeth with her and often thought of her. Cassie guessed that she must've died in the Third or Fourth Wave.

Crisco
A greasy-haired "creep" at Camp Ashpit who showed interest in Cassie and gave her jewelry he took from corpses ashes (he loved digging through corpses to look for jewelry). Despite her aversion to him, he was attracted to her and kept trying to convince her that they should kiss. One time Cassie hit him so hard that blood poured out from his nose. Whenever they were civil, they often would talk about the Others. He was killed by a Silencer (Branch) who went and snapped his neck right before the rest of Ashpit was massacred and then destroyed.

Colonel Vosch
Cassie first meets Vosch as he presents himself as the man who has come to help them all. Cassie believed it until the moment that things started getting odd with his request to take the children from their camp and have everyone else rounded up. She was able to get away and witnessed him shoot and kill her father. Since then she has had the deepest distaste for him. A distaste that intensified when she broke into Camp Haven and he revealed his manipulations on the children there as well as tried to have Sammy killed. It got even worse when Ben confided in Cassie that Vosch gave him hope until he savagely took it away and Cassie believes that Vosch did this intentionally to hit them all even harder like he did with the escalating terror of the waves he used.

Ringer
Cassie has had an adversarial relationship with Ringer almost from the moment they met. She found herself to be a little jealous of Ringer's natural good looks and of her tough exterior. Whenever the two of them try to start up a conversation it quickly becomes tense and they start to be at opposite ends of an argument. Ben once had to come in between the two of them when they were close to coming to blows with each other.

Appearances

 * The 5th Wave
 * The Infinite Sea
 * The Last Star

Trivia

 * Her favorite color is green which is stated in The Infinite Sea; in The Fifth Wave, it is purple and red.
 * She can touch the tip of her nose with her tongue.
 * After the 3rd Wave, she gets a strong dislike of birds.
 * Cassie starts to feel left out with the rest of Squad 53 as everyone, including her brother, has their own nicknames while she doesn't.
 * Cassie is the prime narrator in The 5th Wave. The other narrator in the book is Ben Parish.
 * In The Infinite Sea, Cassie is again a narrator and she is joined by Ringer, Evan, as well as Poundcake who narrates a chapter.
 * Cassie is the only one to serve as a narrator for all three books.
 * Cassie's favorite book of all time is Where the Sidewalk Ends, by Shel Silverstein. She mentioned this in The 5th Wave and Evan Walker told Sammy this after her death in The Last Star.