Jimmy Nickels, Shawn and Gus' childhood bully, has called and is coming to see them at the Psych office. The guys are scared but determined not to give up their lunch money again, until they open the door to see that Jimmy has not grown an inch since they last saw him, which is one of the reasons he became such a successful jockey. He's come to hire them. He's been losing his races and he doesn't know why. Despite Gus' protests, Shawn agrees to take the case. He has felt guilty ever since he turned Jimmy in for hitting a teacher with a spitball, which led to Jimmy's expulsion. Shawn feels he owes him.

Two teenagers, Shockley and Goddard, come to the Psych office to hire Shawn and Gus for a case. They need help and the police won't take them seriously since they are kids. One of their teachers at the Meitner School for gifted students has killed someone and in two days, he'll kill again. The problem is, they don't know which teacher it is, who he killed or who his next victim will be. When they broke into school late one night to pull a prank, they accidentally hacked into a cell phone call being made from the campus. The only other information they could get is that the killer has a deep voice and a cousin named Muriel.