When Shawn's partner Gus decides he doesn't want to be a detective any more and gets a 'real' job, Shawn is thrown into a state of worry. Is this the end of Psych? Is it the end of Gus? But when a fellow executive at Benson Pharmaceuticals turns up dead, Gus suddenly realises he needs Shawn more than ever to solve the murder before he's forced to take an early - and possibly permanent - retirement.