When the twins visit Annie Hobbs in the physch ward she reveals, "It was the snake."
Sutton points out the snake tattoo on Derek's wrist to Ethan. The pair attempt to question him but are split up by a teacher.
Sutton and Ethan wait outside Derek's last class to find that he left school early, claiming he had food poisoning.
Thayer, Ethan, and Sutton show up at Derek's house. His mother reveals that the night of Sutton's birthday party, Dan Whitehorse gave him a ride home after his car broke down by the lake.
Emma (as Sutton) is at the Mercer House, scolded by Ted and Kristin for the real Sutton's behavior.
Thayer and Sutton check out Derek's online profile, noting he spends a lot of time at the body shop.
Ethan asks Dan why he thought he and Sutton had crashed the Mercer car into the lake, when Dan himself had found Derek drenched,on the side of the road by the lake and in need of a ride that night.
Dan Whitehorse expressed a desire to re-open the Mercer car case to Alec Rybak. Alec insists it would be a waste of time.
Day of Derek's Death
Emma (as Sutton) waits for Mads at the library. She makes a call to Alec to see where Mads might be.
Ethan and Sutton arrive at the body shop to question Derek about the night Sutton's car went into the lake. They find Derek inside the shop- he is tense and swings a tire iron at Ethan, who punches Derek in return. He almost answers their questions, but...
A car pulls into the body shop's parking lot. Derek is getting up from Ethan's punch as Ethan and Sutton flee.
Ethan and Sutton are pulled over by Harry half a mile from the body shop for having a tail light out.
Rebecca meets Alec at the door of the Rybak House.
Derek's body is found outside the body shop.
Harry mentions to Dan that he pulled Ethan over nearby the night before.
Dan tells Ethan to run.
Thayer overhears a phone conversation between Alec and Dan concerning Derek's death.