Castle is confronted by his past when he gets involved in a case that, for him, stretches back thirty years and was his inspiration to become a writer. Thirty years before, he witnessed a murder, but no body was ever found and no one was reported missing so no one believed him. However, a similar case crops up and Castle jumps on the chance to solve his first mystery with his friends. They are able to eventually identify the girl Castle saw murdered and catch a disturbed man they believe did it. However, while visiting the man's psychiatrist, Castle recognizes his voice instantly – the psychiatrist is the murderer. With the help of Beckett, Castle searches a barn belonging to the psychiatrist and discovers a book of his victims. Castle fights with the killer and ends up being held at knifepoint, and Castle ultimately kills him with Beckett's gun. Meanwhile, Beckett is offered the chance to run for state Senate, as well as the chance to become captain of her own precinct, and Castle is given an award for his writing that he dedicates to his family and friends.