Psych: Season 4, Episode 15

4 - 15: The Head, the Tail, the Whole Damn Episode

A shark attack victim washes up onshore, and Lassiter notices what appears to be a knife wound on the body. With that, he thinks that the victim was actually murdered, which impresses Shawn since it's a theory that he would come up with. Meanwhile, Henry begins flirting with a shark expert (Jeri Ryan) and a fisherman (Michael Hogan) lends Shawn and Gus a hand.