Stewart Gimbley bursts into the Psych office looking for help. He went to the police first but was referred to Shawn and Gus instead. Stewart wants the guys to lock him up and observe him overnight. He gives them a gun with silver bullets for their protection, because Stewart believes he's a werewolf. He thinks he killed a lamb last night and is worried that tonight he'll do worse. He offers them three times their rate, which they readily accept, thinking this will be easy money. They tie Stewart up but then fall asleep themselves, only to wake up to the sound of the window shattering. Stewart is gone and a tuft of grey animal hair dangles from a shard of glass. Later that night we see two hunters brutally attacked in the woods.
Spoilers ahead. Coverage follows the scope labeled below.
Complete story — includes the ending
A man named Stewart Gimbley ( Joshua Malina ) believes he is a werewolf, so he offers Shawn and Gus three times their normal rate to tie him up and observe him. Unfortunately, they fall asleep and wake up to find Stewart missing, their window broken, and a tuft of animal hair. Their investigation leads them to a psychiatrist ( David Naughton ) and a Wiccan ( Larisa Oleynik ), each with possible secrets. This is also the episode where Henry has to keep touching a truck to win it.