Not much is known about Sebastian's early life prior to his police career other than him being a Krimson City native. During his time in the police force, Sebastian originally held the rank of Sergeant prior to being promoted to the crime division, where he met his junior agent and later wife Myra Hanson. Despite their differences in methodology and ideology, the duo hit it off surprisingly well, leading to good field synergy and co-operation. This partnership soon turned into a full-scale romance, one that was escalated by Myra's field injury and sick leave. Soon after, they were married, and the fruit of their union was their loving daughter Lily. Sebastian's life was idyllic, being a loving husband and father, but even so buried himself in work.
But, his happiness was not to last, as a housefire burned down Sebastian's family home and presumably his five-year-old daughter along with it. Worse yet, his wife began acting strangely afterwards, seemingly convinced that the fire was staged and their daughter wasn't dead. In full denial of the truth, however, Sebastian brushed aside Myra's pleading and insisted on moving on with their lives. Myra herself disappeared soon after, causing Sebastian to sink even deeper into despair and turned to alcohol and cigarettes to wash the grief away. Slowly, however, his passion for work eroded, as well as his sense of perspective and composure, as he further spiraled into despair.
Shortly after his wife's disappearance, Sebastian's new partner, Joseph Oda, who was assigned to him as Myra's replacement, noticed his alcoholic streak and reported the case to Internal Affairs in an attempt to get his partner back on track. While it did save Sebastian's career, it ultimately put a great strain on their relationship. Since that time Sebastian has returned to the job but is never without his hip flask. He still feels responsible for the tragedies that befell him and shrugs off any offers of help.
At some point, Sebastian was assigned to mentor a new detective, Juli Kidman. He showed her the ropes and treated her as an equal despite her age. He was impressed when she was able to break their first case on her own.
The Evil Within
The series' plotline begins with Sebastian, Joseph and Juli being driven to the Beacon Mental Hospital by officer Oscar Connelly, sent by their precint to investigate the reported "multiple murders" following the disappearance of the previous dispatch. As they arrived at the scene, Sebastian and Joseph went inside to find the aftermath of what looks to be a massacre with only one survivor, the hospital's chief of staff Dr. Marcelo Jimenez. While Joseph tends to the shaken doctor, Sebastian goes through the CCTV footage and finds the previous dispatch being taken out by a cloaked supernatural assailant who, unbeknownst to him, has appeared in the room and was readying to strike. Sebastian turned around just in time for the hooded man to stab him with his orbitoclast, knocking him out.
He then wakes up in a strange basement and finds himself hung by his feet amongst several corpses. A large, masked man then appears, forcing Sebastian to play dead until he returns to his kitchen, at which point Sebastian manages to cut himself loose with a knife he retrieved from a nearby corpse, lift the keys from a meathook and makes his escape. Before he could leave, however, Sebastian accidentally trips an alarm wire, alerting the masked butcher to his attempt, who then manages to chase him down and cripple him with a chainsaw wound to the leg. Despite his injury, Sebastian manages to escape into the sewers, and outmaneuvering the man once more to make it to an escape elevator where he is taken to safety.
At the top of the elevator, an earthquake occurs, forcing Sebastian to flee the building. He manages to escape, but finds Krimson City itself crumbling apart. Officer Connelly then arrives in an ambulance, beckoning him to hurry up as the ground beneath the vehicle gives away. Sebastian barely makes it in as Connelly drives with the roadway crumbling behind him. Unknown to them, the figure from before observes as they drive away and disappears from view soon after. As Krimson City continues to fall apart around them, Sebastian is informed that Joseph never made it out of the hospital. Leslie, an asylum patient, begins repeating the words "fine" and is comforted throughout the ride by Kidman and the doctor they found earlier. After a long run through the devastated city, Sebastian looks up at the rear view mirror and sees the hooded figure standing with the backseat passengers. Shocked, he looks back, only to see Kidman, Leslie, and the doctor. The ambulance begins losing control as Connelly appears to degrade. Leslie's chanting changes from "fine" to ''fall", which turns out to be right as the ambulance then falls off a cliff. Sebastian then blacks out when the ambulance hits the ground.
After having a nightmare of seeing a lone Haunted crawling up to him, Sebastian wakes up in a hospital, and the setting is filtered black and white. As Sebastian heads towards the door, a nurse appears and escorts him from his 'room'. He is then asked to sign in so as to not 'lose his future memories'. Sebastian is then escorted further into an ominous looking room with a single leather chair in the middle. At the nurses' coaxing, Sebastian eventually sits down in the chair. Strangely, the chair then changes into a metal chair. Before Sebastian can get up, the chair latches on to his hands and legs, trapping him. With the jar found earlier in Sebastian's room, the player unlocks access to Sebastian's mind. This is later used as a way to upgrade Sebastian's abilities with the Green Gel found throughout the game. After Sebastian uses the gel, he asks the nurse if he is going crazy. The room then bursts into flames after the nurse replies "Now what makes you say that?"
Sebastian then awakes to realize that he was in the destroyed ambulance after it fell off the cliff in the previous chapter, explaining why the room burst into flames before. He then staggers out of the wreckage gravely injured. As he proceeds to wander through the forest that the ambulance landed in, he finds a tent with a man crouched over something. Sebastian picks up a revolver and approaches the man. After turning around, the man is revealed to be Officer Connelly, eating a head. Sebastian kills the reanimated Connely and continues. He then finds Leslie behind a trip wire, indirectly saving Sebastian from death. Leslie runs away before he could help.
Making his way through the Haunted, Sebastian witnesses the process of becoming the Haunted. While being chased by a horde of Haunted, Sebastian makes it to the exit which is blocked by a gate. To escape, Sebastian jumps into the water below the bridge. The chasing Haunted give up and leave.
Claws of the Horde
Sebastian gets himself out of the water and comes to a village. In the village, he finds the same doctor from the hospital. The doctor, named Marcelo Jimenez, tells him that Leslie was one of his patients and went through the nearby closed gate. As the horde of Haunted builds up, Jimenez volunteers to distract the enemies while Sebastian goes for the gate.
The gate has no crank and is unmovable. Sebastian realizes that he needs a chainsaw to cut through the chains. He then encounters the Sadist from Chapter 1 who is restrained by chains. The Sadist breaks free and after a tough battle, Sebastian kills him and uses his chainsaw to open the gate. As he and Jimenez walk through the gate, it shuts itself behind their back.
Jimenez informs Sebastian that his brother Valerio, who cared for Leslie before him, runs a hospital not too far from the entrance. Once they enter the hospital, they find Valerio with his back turned, performing surgery on a man. When Sebastian approaches Valerio, it is shown that Valerio isn't saving the man but instead mindlessly slicing him open. Valerio himself is revealed to have turned into one of the Haunted as well. After Sebastian kills him in front of Jimenez, a vision of Valerio's living death is shown. Valerio is beginning to cut open the same man but begins complaining of an itch on his head. Valerio then scratches his head so much he tears off some of his own scalp, killing him. Jimenez then starts mumbling about how "Ruvik" couldn't have killed Valerio.
Leslie then screams from outside, running into a house. Sebastian and Jimenez chase after Leslie into the basement. After reaching Leslie, the door appears to open by itself, until Sebastian is attacked by an invisible Haunted forcing Sebastian to kill it to proceed. When they go back to the stairs, it turns into a wall.
Ruvik appears and separates Sebastian from Leslie and Jimenez into an unknown area. Sebastian makes his way through the hospital and eventually encounters a four armed Haunted named Laura. Sebastian escapes but then is sent into a different area of the hospital by Ruvik.
Making his ways through the hospital full of invisible Haunted and deadly puzzles, Sebastian finds Joseph connected to a bath tub. After freeing and healing Joseph, the duo continues together to get out of the facility. However, Sebastian starts to worry after Joseph almost becomes a Haunted and attacks him.
After getting out, they find Kidman, trapped inside a filling tank. Both of them fight waves of Haunted, some armed with sticks of dynamite before they can help Kidman. Joseph then tells Sebastian that to open the tank; a code must be used on a panel. Sebastian must unlock the tank before Kidman drowns.
After getting Kidman out, she and Joseph are then separated from Sebastian to the sewer below, and Sebastian quickly follows. As they reunite again, the trio then are separated again by Laura. Sebastian is moved to the area where Laura is, but eventually he discovers that fire is the only weapon that is effective against the creature. After a firefight, Sebastian moves on and goes into a room with the STEM machine. He sees a flashback with Ruvik conducting an experiment on Leslie, determining him as the first to survive linking to his brain. Snapping back to reality, the machine becomes active, releasing three Haunted which are connected to the machine. Sebastian must knock them down and pulled out the cord to defeat them. In the end, the machine explodes and knocks Sebastian unconscious.
Losing Grip on Ourselves
Awake in the Safe Haven from a nightmare of an eye surgery, Sebastian is in the staff room by a desk. On it are some photographs: a lighthouse, a church, a cemetery, and a hole in the church. As he inspects the hole, everything goes dark. He walks to the patient wing, where he sees Tatiana patrolling her way down a set of stairs that has appeared to the right of the mirror at the end of the hallway. Once he follows, a hallucination of the Keeper is seen. As Sebastian finds Leslie in one of the cells, Leslie slowly turns around. His face turns out to be a mirror, which teleports Sebastian back to the real world.
Sebastian ends up in some coastal building of Cedar Hill Church, where he finds Joseph unconscious again. They fight through a seemingly endless army of Haunted and end up having to kill four Haunted, who are operating devices that rain down harpoons. As they come close to the lighthouse, Joseph is separated, and Sebastian must fight another Sadist to regroup and continue.
Arriving at the top, Joseph spots two Haunted using a guillotine to execute helpless victims, and thinks he can take them, when he accidentally sets off a tripwire, which blows up the bridge, leaving Joseph knocked out and separated from Sebastian. The two Haunted start to drag Joseph to the guillotine to execute him, and Sebastian must save Joseph before the Haunted decapitate him. After Joseph helps Sebastian cross the gap, Joseph steals his pistol and aims at himself in the head, wondering if it's worth trying to get away. However, Sebastian intercepts before he can pull the trigger, in which Joseph states that Sebastian is slowly drinking himself to death.
They arrive at a cemetery, in which both of them starts to catch some patterns. They both seem to be experiencing "jumbled up memories". Shortly after, Joseph has some pains and Sebastian helps him rest in a nearby house. It is revealed that Joseph reported Sebastian at some point, and talks about how "the accident" wasn't his fault. Once Joseph musters his strengths and moves onwards, he sees Leslie and Kidman entering the church. Forcing to use the path in the cemetery, Sebastian encounters the two Giants, Neun and Zehn. After defeating them, Sebastian sees that the route to the church was cut. With no choices, he and Joseph use the underground path. Sebastian then teleports back to the Safe Haven without notice.
After solving a sacrificial puzzle, they encounter the Sentinel. The Sentinel knocks Joseph down, forcing Sebastian to fight the monster alone. Once they're out of the arena, Joseph informs that his glasses is in the area where the Sentinel is. Sebastian has to retrieve the glasses to go to the church to catch up with Kidman.
Once they enter the Cedar Hill Church, Joseph starts to question whether or not he should continue fighting the urge to turn into a Haunted. Joseph soon loses consciousness, and Sebastian injects a syringe into him, hoping it will help. Ruvik then appears and transports Sebastian to the underground catacomb, where the Keeper awaits.
To move on, Sebastian must obtain three stone lithographs to lift the blockade, encountering AlterEgos along the way. Once done, he descends a staircase, where he meets the Keeper, who triggers a spike trap. Sebastian then steps on a barbed wire trap and must get out before the spikes crush him. Then he must run to the other side while stepping on the traps to avoid getting crushed.
Finding Leslie in a caged cell, Sebastian frees him, but he starts to panic and runs away, triggering a trap which locks Sebastian in the room with the Keeper. After the first Keeper is defeated, poisonous gas starts to fill the rooms. Sebastian must shut all the valves as he battles with the spawning Keepers. In the end, The Keeper decapitates himself and throws his safe head to the ledge where Sebastian is, and launches itself towards him. Sebastian throws the attacking safe back down to the floor, and crushes it with the spike trap as it fully respawns its body.
A Planted Seed Will Grow
Sebastian enters the cave, inside of which resides numerous AlterEgos. Later on, whilst opening a passage, Sebastian accidentally releases The Babies. As he passes the last puzzle, he is then teleported to the hallway, reaching the room with the STEM machine. In there stands Jimenez. He tells Sebastian that the world was created by Ruvik, and thinks that Ruvik wants them dead.
Jimenez then disappears. Sebastian is then pursued by the Amalgam Alpha into the Safe Haven. Thought to be safe, Ruvik suddenly appears in front of Sebastian.
The Cruelest Intentions
After seeing a nightmare of him getting burned alive, Sebastian goes to Tatiana. She is looking at a portrait of the Victoriano family. Seeing that Ruvik's face was missing, Sebastian is then jump-scared by Ruvik.
Walking down the corridor of the patient wing, Sebastian arrives at a path toward an abandoned mansion of the Victoriano's. As he walks in, Jimenez is seen taking Leslie to the hallway behind the vault, which closes behind them. To open the vault, Sebastian must find three test subjects and insert a metal rod into their brains in a gruesome experiment correctly while being chased by Ruvik. Every experiment completed will reveal what happened in the mansion in each room via flashback.
Walking down the hallway behind the vault, Sebastian gets moved to a room with a ghostly young Ruvik. After a little chasing, the young Ruvik then turned into a giant blood cell-like creature. Sebastian cannot defeat him and therefore, he is forced to run. Encountering spikes traps and cage mazes, Sebastian escapes, only to find himself in front of a barn in the middle of a sunflower field. He can see the past about Ruvik and Laura, and how Laura died from the barn fire, sacrificing herself by pushing Ruvik through a tiny window above the tall barn doors.
As the barn burns, Sebastian manages to escape but gets pushed back by the creature. Sebastian must fight all the Haunted while avoiding the creature. As everything ends and the barn burns down, Sebastian's vision ends and he returns to the hallway and enters the basement.
The Craftsman's Tools
Entering the basement full of deadly machinery, Sebastian sees a memory of Jimenez and young Ruvik before moving into the next area. Sebastian then feels sick as in the next area, there is a giant blade attached to a rotating carousel. Sebastian must make it through without getting his head chopped off by lowering his body into a crouch position, making him vulnerable to the Haunted present. Moving deeper, he sees that to move on, he has to turn on the power to open a metal door. He finds a battery and activates the power, but then encounters deadly machinery and Trauma along the way back.
Continuing his journey, Amalgam Alpha teleports Sebastian to the abandoned asylum, where the haunted form of Laura is waiting. To get to the elevator, Sebastian must proceed through the morgue and furnace, which means facing open incinerator, which is blasting fire outwards. Laura will chase Sebastian until he reaches the elevator. As he makes it, Laura grabs his neck and attempts to choke him, but Sebastian presses the elevator button, cutting her arms off as the elevator descends. Ruvik then appears but doesn't attack. He warns Sebastian that no one can stop his plan.
As the elevator reaches the floor, Sebastian finds himself in the mansion once again. He walks down the hall and meets Jimenez, who was about to start a test on Leslie. He informs that Leslie had made it out of Ruvik's world, and is the key to getting them out too. As he attempts again, the Amalgam Alpha interrupts and kills Jimenez. It then pushes Leslie and Sebastian. Sebastian flies through a fence and lands in the underground parking lot. Sebastian must fight Amalgam Alpha to get to the surface.
Arriving on the surface, Sebastian sees Krimson City in destruction after an earthquake, but only the Beacon Memorial Hospital remains perfectly unharmed. He fights his way through more Haunted, now in armors and armed with assault rifles. He also encounters the Doppelganger. Later he sees Kidman escaping from a mob of Haunted. Sebastian calls to her and tries to find a way to get across to her, but he has to swim while avoiding being eaten by the Shigyo. Once he reaches her, they continue to search for Joseph and Leslie.
When reaching the warehouse, Sebastian then turns into a Haunted and attacks Kidman after warning her. Kidman shoots him, but he later becomes normal. Kidman locks Sebastian in and walks away, but Sebastian is helped by Leslie. However, Leslie once again runs away before Sebastian can help. Going deeper, he finds himself in a room filled with flammable gas and mannequins as several Haunted and Trauma patrol, preventing him from using any firearms as it would make the warehouse explode. As he escapes out of a window and gets down to ground level, he sees Joseph and goes to him.
Joseph is glad to see Sebastian alive, and informs him that he has had no more "episodes." He tells Sebastian that he found a bus. Before he can get the chance to start driving, Kidman rushes in and starts the bus, when they are attacked by the Heresy, who rips the top of the bus off. Kidman drives through the ruins of the city as Sebastian and Joseph attempt to fight off Heresy. After an intensive fight, Heresy is finally killed by a falling building.
Joseph explains that even though the world was changing, the lighthouse was still the same distance, and it can be seen everywhere. Suddenly, he gets shot, forcing Kidman to stop. She tells Sebastian to find a medical kit from the ambulance on the other side of the highway. She volunteers to go, but Sebastian goes by himself to make sure that Joseph is safe.
When he gets the Hemostat and starts to return, a Haunted in a truck with a heavy machine gun attacks. Sebastian must get to the machine gun and shoot down all enemies before moving on. Once they're off, Kidman drives down the road. They then confront Ruvik, who levitates the bus, and sends it crashing into nearby apartment blocks.
Kidman is once again separated from Sebastian and Joseph. They both begin to descend the building but get separated when an elevator gives away. Sebastian encounters acid traps set by Doppelgangers. The Keeper also appears at times, forcing Sebastian to be stealthy.
Once arriving at the bottom floor, Sebastian finds Joseph fighting the Keeper. Suddenly, Ruvik changes the kitchen room into a death trap. Sebastian must disarm the acid trap to exit the room while avoiding fire, spikes, and robots with spinning blades. Having arrived in the meat locker, Sebastian must follow Joseph up the elevator, but must fight the Keeper long enough until the elevator arrives.
Seeing and eventually approaching Kidman and Leslie, Sebastian witnesses Leslie stop everything around them from moving. Juli pulls out her gun to shoot Leslie and apologizes then says it wasn't his fault. Sebastian proceeds to try and stop her, but he learns that Juli had her own set of orders from someone. However, she says she's going against them because she can't let Ruvik have Leslie.
Once she turns to Sebastian, there is a brief moment of confusion on her face before Joseph runs to Leslie. Leslie screams very loud, loud enough to shatter the nearby by windows and runs away. Kidman tries to shoot him, the first shot misses but her second hits Joseph because he jumped in the way. As she runs after Leslie, the ground gives way and Sebastian falls through the earth.
Sebastian wakes up in a subway station and wishes that Joseph is okay. Coming closer to the train bridge, Sebastian fights through the Haunted and eventually enters the hive where Quell and many AlterEgos dwell. He comes to the elevator, where he has to connect the circuit and power the generator. In the middle of cranking the generator, Quell interrupts and flings him into the arena where Sebastian fights it. After defeating it, he powers the generator again and use the elevator to go up.
Reaching the train car connecting the two buildings, he is warned by Ruvik with three steel beams inscribed with the words 'You will suffer.' On the midpoint of the bridge, Ruvik comes and casts a storm, shaking the train. Sebastian escapes before it falls into the valley.
An Evil Within
After waking up from the nightmare of Sebastian killing himself, Sebastian finds out that the ward is empty, and Tatiana is gone. Sebastian checks her reception desk, where he finds his last personal journal. Suddenly, the place shakes. Sebastian then finds Leslie, who guides him to the hospital, but gets separated at the last point.
At the surface of Krimson City, he stands on the road in front of the hospital, seeing the beacon of the hospital. From there, he finds Leslie at the beacon. As Sebastian follows, an anonymous patient tells him not to look into Ruvik's eyes, after which he dies. Sebastian is then grabbed and choked by Ruvik, but he smacks Ruvik with his lantern, burning his robe off, and accidentally looks into his eyes. Suddenly, he is back at the entrance, but in a bloody arena world. Sebastian must survive all the battles and traps in order to reach Beacon Mental Hospital again. At this point, Ruvik admits that he created the world.
Arriving at the top floor, Sebastian finds himself sleeping in a tub connecting to the STEM machine on the floor below. At the same time, Sebastian hears Leslie as he burst through a door, running away from Kidman. He hides behind Sebastian as Kidman arrives. After a brief conversation between the two, the world changes. Leslie walks toward Ruvik and turns him into liquid as he touches him. The liquid is then fed into the giant Brain. The world then tilts, and Sebastian flies out of the window into the area where the final battle awaits.
Sebastian lands on a giant brain as Ruvik, now evolved into Amalgam, attempts to crush Sebastian. Sebastian, unable to do anything but run, ends up flying into a truck with a mounted gun. He must shoot all of Amalgam's arms to survive, and must also aim at the brain, where Ruvik is. Sebastian loses control of the vehicle and gets impaled on a sharp piece of building frame. However, a dead Sadist falls from the sky and happens to have a rocket launcher in its hands. Sebastian takes the launcher and manages to do substantial amounts of damage to Amalgam before he is pulled off and lands on the brain again. Before Amalgam kills Sebastian, he gets one final shot off with his pistol that hits Ruvik and kills him.
Sebastian wakes up, hooked to the STEM machine. After a hallucination of Ruvik, Sebastian ends everything by disconnecting and destroying Ruvik's brain.
Sebastian wakes up again in the STEM machine. Kidman, who was checking his heart rate, closes the monitor and gestures Sebastian to play dead. As the staff goes away, he wakes up and removes the connected cord. He sees Connelly and Jimenez connected to the machine, but they are already lifeless. Sebastian leaves to find Leslie, who went away first. As he comes to the reception, a SWAT team comes in, and checks if Sebastian is alright, but he states that he just want some fresh air. When he walks outside, however, he sees Leslie walking away confidently (implying that Ruvik has taken over his body), but before he can go to him, a headache strikes and Leslie suddenly disappears.
Sebastian is the deuteragonist of The Assignment. He appears a few times in this DLC.
The first are when Juli sees him and Joseph wandering the MOBIUS building a couple of times. To them, it was Beacon Mental Hospital.Then she sees them again in the Water Chamber and when she falls out, Sebastian and Joseph are there. Joseph asks her if she was alright before they fall through the floor.
After that, Juli doesn't see Sebastian again until later in the game when she finds Joseph, and they fight off a bunch of Haunted. Then while the three of them walks down a hall flooded with blood, Sebastian gets a headache induced by Ruvik and runs off. She doesn't see him again for the rest of the DLC.
Sebastian is the deuteragonist of The Consequence. He appears a few times in this DLC.
Sebastian is seen a lot more in this DLC. The first is when Juli sees a memory of him and Ruvik talking. Juli then proceeds to say she feels bad for him and that 'he doesn't have anything to do with this.' She sees him again later at the construction site. She sees him again from her higher vantage point and says the same thing as before.
After she kills Shade, they see each other again briefly before he turns into a Haunted and tries to attack her. Juli nearly shoots him but then sees Ruvik behind him, so she barely misses Sebastian and hits Ruvik instead, causing him to disappear. Sebastian passes out while leaning on her (practically laying on her), and he turns back into a human. Juli then hugs him and says, "I'm sorry for putting you through this. I don't want to hurt more than I already have." She then locks him in the room and leaves him.
Not too long after they see each other again when she is running from both The Administrator and the Heresy. Sebastian and Joseph are on the bus before she runs into it and tries to start it. She then drives all three of them away from the Heresy as The Administrator stops chasing her and disappears.
A Ghost is Born
She doesn't see him again until she is at the playground. At first, she doesn't even realise it's him. She thinks it's The Administrator, but when she turns around, he turns into Sebastian. She is confused for a moment before she runs after Leslie and Sebastian falls through the ground.
Later on, she doesn't see him until she's chasing Leslie at the top of Beacon Mental Hospital. Sebastian tries to stop her while blocking Leslie from her range of the shot. She tries to explain to him what's been going on and why she's doing this, but Ruvik interrupts them. Ruvik turns Leslie into the liquid which is then absorbed into the giant Brain.
After this, they see each other in the real world. Juli thanks him for stopping Ruvik then she turns off his monitor. Sebastian wakes up, and she signals him to lay low. She then lies to MOBIUS that he's dead so that he won't be taken away, and so he can escape later.