No Trout About It

Plot:

Petty private investigator Leo Quinn hires Psych to find out who fatally poisoned him, and why. It turns out to be about his code for a rich old client's diamonds-stuffed safety deposit, the key being used by an employee, involving infidelity and revenge. It's all told through the contradictory explanations given by Shawn and Lassie to FBI agent Harris Trout, who is mandated to audit and clean up the SPD, targeting the chief, Carlton, moonlight-stripper Buzz and even then Psych consultancy.