Unforgettable Episode 1.12 Butterfly Effect

A college coed is found dead in a fraternity house. The case is linked back to a drug running business connected to the frat house and some of it's members. Carrie uses her memory to find that the boy who was murdered was an unwilling member of this drug ring. He was a loner and a good student, but needed the money. Carrie infiltrates the world of hazing and fraternity parties to get to the bottom of this case. This is the one episode where Carrie loses her memory because she is drugged at a party - and has to put the pieces of the puzzle back together in her own mind.