A dead woman, Pam Hodges is found hanging from fishing wire, inches above the ground. She looks exactly like Dr. Lanie Parish. Pam was a hooker who had plastic surgery to look like Lanie. She even had the same tattoo.
Later, a dead ringer for Esposito is found murdered the same way, only he was slowly tortured first. Dr. Kelly Nieman knew both victims and performed the surgery but there isn't enough evidence to tie her to the murders.
Beckett and Castle realizes that the doppelgangers signed out all of the 3XK records before they were killed. All of Jerry Tyson's files are gone.
A video leads detectives to security guard Carl Mathews. He killed both victims and several others but refuses to admit any connection to Tyson. He does tell the detectives that they only think they have things figured out.
When the team goes to arrest Dr. Nieman, they find she's disappeared. There's a note on her desk that says Better Luck Next Time and a pen. Inside the pen is a memory stick. It contains a song with the lyrics, "We'll Meet Again."