A homeless man is arrested for the brutal stabbing of a wealthy heiress, Summer Davenport. The team goes to investigate the crime scene and is surprised to find Delko is helping out the defense as their forensics expert and observing their evidence gathering process. The man, Zach Finley, admits to breaking into the house and staying the night but claims he never heard or did anything. They find his prints on the murder weapon and when they reexamine the scene, they discover Summer may have also been raped. Horatio tests Zach's DNA to see if it matches but they discover Zach lacks the certain parts to have done the awful deed. Going on the lead of what Summer's stomach contents were, they find another woman who was raped the week before. The one thing they had in common was being serviced by the same computer software repair company & when they question the woman she tells them after the rape it seemed as though it was a completely different man who tried to stab her. Horatio begins to suspect that Zach isn't so innocent as he claims and they track the woman's computer to find out the tech, Justin Porter was the one who worked on it and find him in a storage facility watching all the videos he took of his rapes. In questioning Justin, the team discovers both he and Zach were a team and that they met working together in the years prior. Zach admits to Horatio that he and Justin completed each other. Horatio puts them away so they indeed could be together forever.