Marty Kalish is an investment banker and in love with a married woman named Rachel. When the husband disappears one night -- and Rachel says a stranger has broken into their home, shot her husband and left with the bleeding man in tow -- Marty is one of the first to be questioned. With few likely suspects, the police arrest him for murder. We know Marty was present on that night. We know he has a motive. We know he has even manipulated evidence. We know he's guilty of something. But is it murder? Marty and Rachel see each other after the night in question, but cannot speak. He receives a phone call and the message "I saw what you did". From that moment on, he knows an unidentified witness is out there. He prepares his defense and hunts for the missing third party. Piece by piece, Marty reveals more of his past and the night of the murder. He confesses in one moment, but gives us reason to believe in his innocence the next. At the trial, the witnesses -- including a reluctant Rachel -- are damning, but Marty's attorney deconstructs the events and raises the possibility of reasonable doubt with masterful precision. The back and forth "did he/didn't he?" questions about Marty's innocence become more urgent as we get closer to the trial's end. As one lawyer says, the truth is really only the elusive middle ground between two versions of the same story. If the court doesn't find that truth in Marty's case, this trial will be his last.