This episode is well written and funny.
It starts when Lassy throws himself a party and invites everyone to celebrate his solo case-solving and it turns out that the case had a loop and they main suspect was sent to a psychiatric facility and they doubt that he was faking it in order to get out of the crimes.
Henry decides to send Shawn as an undercover patient to look closer at the suspect and decide if he is truly guilty or not. The funny thing is that Gus is sent there too as an undercover Janitor and security guy. It is hilarious when he follows Shawn and restrains him.
Another funny moment when Gus falls in love with a hot girl that has multiple personalities.
Shawn solves the crime and discovers that the victims young brother is the one who was giving him wrong pills and blame the crimes on him.
Kenny G solves the crime again... I mean Shawn :)