TM 05637 was created to be a killer. Genetically engineered for superiority, he was facing a life of missions, blood, and death until his creator decides to set him free. On the run from those holding his leash, he is found by David Conley, an ordinary store owner who stumbles upon a remarkable find. Renaming himself “Tim,” TM 05637 sets out to discover what it means to have a normal life. Through his friendships with a young boy dealing with a nightmarish family life, and David’s mother, who decides Tim is perfect for her son, Tim slowly discovers his humanity. Even more importantly, David teaches Tim about the power of love. But General Woodard, leader of the project that created Tim, threatens their happiness with his determination to bring his evasive quarry permanently to heel. As the search net closes ever tighter around him, Tim must find a way to thwart his pursuers so he can stay with David and live out his dream.

Sequel to To Be Human Tim—designation TM 05637—thought he'd escaped his fate as a genetically engineered supersoldier when David Conley offered him a precious chance at a normal life. But General Woodard, Tim’s handler, captures them, crushing Tim’s short-lived dream. Thrilled at the return of his pet killing machine, Woodard plans to break Tim’s resistance by forcing him to virtually kill David. Fortunately, Dr. Paul Anderson, the scientist who created Tim, offers them a chance at freedom. But a deadly weakness implanted in Tim’s DNA threatens his life. Without regular doses of a special medication, Tim faces debilitation and even death. In search of a more permanent solution, Dr. Anderson enlists David’s help to infiltrate a base where a cure is kept. But David is unable to fully trust Tim, haunted by seeing Tim killing him in Woodard’s brutal training simulations. Desperate to protect David, both from the general—and himself—Tim struggles to find the strength to leave the man he loves while completing the mission. With Dr. Anderson’s help, Tim and David try to stay a step ahead of the general, knowing they must reach the cure before mistrust tears them apart, Woodard catches up with them, or the clock runs out on Tim's life.