Walter was in a mental institution for 17 years when judged incompetent to stand trial on manslaughter charges from some of his `tests`. The only person who could visit him was his son, who didn`t. Enter FBI agents Olivia and John, who are lovers. While investigating a freak airplane disaster where all died mysteriously, John is hurt by the chemicals that killed the airplane passengers. In order to help him, Olivia looks up Walter via his son, who she blackmails to get access to Walter. She brings him to his old lab in the basement of Harvard University to cure John, which he does. John then turns out to be a spy, and it is him that is supposed dead, but was hooked up to the machines in the end of tonight`s ep.