Jack Ramsay is the main protagonist in the 1984 science fiction thriller film Runaway.
He is portrayed by Tom Selleck.
In the near future, robots are commonplace—a part of everyday life like any other electrical appliance—and are just as prone to malfunctions. When a robot malfunctions, it could pose a threat to people or property. Such robots are known as "runaways." Since they are more dangerous than the average machine, they are handled by a division of the police trained in robotics. The "runaway" squad, however, is treated as an easy and unexciting assignment and often ridiculed.
Sgt. Jack R. Ramsay is a veteran police officer who joined the runaway squad after discovering his previously unknown acrophobia, which resulted in a family's death at the hands of a man he let escape. After years on the job, Ramsay has found himself one of the division's few real experts. His new partner Karen Thompson is enthusiastic about the job, but he assures her there is little excitement involved, saying that mostly it involves flipping a switch. This changes when they find themselves handling a new threat—the first robotic homicide. Investigating a household robot that murdered a family with a kitchen knife and handgun, Jack discovers strange integrated circuits, which not only override a robot's safety features but also direct it to attack humans. These circuits are not hacked chips, but created from a series of master templates, enabling them to be mass-produced.
Despite being unable to learn anything from uncooperative informants who end up dead, Ramsay refuses to give up and soon discovers the perpetrator is sociopathic genius Dr. Charles Luther. Luther, while working for a defense contractor, developed a program that allows a robot to thermographically identify a human from amidst cover and to even differentiate between humans. Seeing the profit potential, he killed his fellow researchers and tried to sell the technology on the black market. A failed attempt to arrest Luther - complicated by Ramsay having to remove an explosive shell from Thompson's arm - results in the recovery of another of Luther's weapons, a smart bullet: a miniature heat seeking missile capable of locking onto a human target's unique heat signature, pursuing them wherever they run, even around corners.
While investigating another of Luther's partners, Ramsay and Thompson find Jackie Rogers, who was once Luther's lover. She double-crossed him and stole the circuit templates, intending to sell them herself. She is scared because she believes Luther will stop at nothing to kill her. When they create a ruse to transfer Jackie to safety, Luther attacks the police convoy with robotic smart bombs. They discover that the bombs are zeroing in on a bug in Jackie's purse; they throw the bag out the window before the bomb reaches the car.
Ramsay decides to make a public appearance with Jackie at a restaurant to draw Luther out, but instead Luther captures Thompson and wants Ramsay to exchange her for Jackie and the templates. Before making the exchange, Jackie gives some of the templates to Ramsay, for insurance that Luther won't kill her. But Luther kills her anyway, after discovering the missing templates. He then fires his smart bullets into the crowded restaurant and flees.
To retrieve the missing templates, Luther plans to attack Ramsay. He uses the police computers to discover everything about Ramsay's personal life, including his son. Once Ramsay discovers his information has been hacked, he races home to find his household robot damaged and his son Bobby missing. Luther calls to confirm he kidnapped Bobby and wants to exchange him for the missing templates.
Ramsay agrees to meet Luther at an unfinished skyscraper. Luther gets the templates while in exchange Ramsay sends his son down in an elevator whereupon Luther informs him that a legion of "assassin" robots—small, spider-like robots which kill by injecting their victims with acid—are waiting to kill the first person exiting the elevator. Thompson arrives and helps Bobby stay out of reach of the robots. Furious, Luther begins firing smart bullets, but Ramsay turns on the robotic construction equipment, creating multiple heat sources which cause the bullets to miss. Ramsay uses this distraction to escape and jump on to an elevator to go down. However, the elevator malfunctions, skyrocketing up to the very top with Ramsay onboard and stops. Ramsay is forced to overcome his fear of heights by reaching a reset button underneath the elevator to restart it, while encountering 3 robot spiders. Ramsay is able to defeat the spiders and restart the elevator downward. The elevator makes a stop on the floor Luther is on, with Luther approaching Ramsay in the elevator and exchanging words with him, causing Ramsay to start the elevator back down again and engage a struggle with Luther during the descent. Ramsay manages to gain the upper hand by pressing the elevator's stop button, catapulting Luther over the side, and the inventor lands on his back, in the midst of his robot spiders. Programmed to kill whoever came down from above, the robots rush Luther, injecting him in multiple places.
Ramsay helps his son down and then cautiously approaches the motionless villain. Screaming, Luther reaches up to grab Ramsay, but falls back, dead, while the spiders self-destruct around him.