Shawn and Gus are attending a triple-feature of famous Alfred Hitchcock films, including (according to a playbill) The Birds, The Man Who Knew Too Much, and Psycho.
After finally finishing the films, they exit the theater and bump into Mary Lightly (Jimmi Simpson), one of the key figures in capturing Mr. Yang a year earlier.
Shawn, Gus, and Mary visit Yang (Ally Sheedy) in the mental institution, where she is kept in solitary confinement.
If you think I'm sick, you ain't seen nothing yet.Shawn leads the group back to the theater, using the crossword to find a specific seat.
After discovering a note, Mary concludes that Yin is working alone, and that, being the opposite of Yang, represents chaos.
During a dream, he sees Juliet, Lassiter, Chief Vick, and his father in classic Hitchcock situations encouraging him to find something.
He remembers that the person in theater was wearing ankle weights, leading him to believe that Mary is Yin.
When he is awakened by Gus, Shawn discovers that, while he was sleeping, someone had vandalized the "Psych" logo on the window to read "Psycho."
When Mary suspiciously arrives with a note from Yin that was left on his doorstep, Lassiter and Juliet trace the clue to a fountain in the park.
At the park, Lassiter and Juliet reach the 39th stair (a reference to Hitchcock's The 39 Steps), but Mary stays behind, blaming his ankle weights.
At Mary's house, Shawn and Gus discover a notebook with several rough drafts of what appears to be Yin's next clue.
When the police and the Psych duo stake out a location referenced in Yin's rough draft, they see Mary entering the building alone.
Shawn and Gus try hopelessly to escape the room and save Mary; by the time they find him, he has been stabbed by the real Yin.
However, Abigail, Shawn's girlfriend, is waiting for him at the airport, arriving back temporarily from a six-month trip to Uganda.
Shawn receives a phone call from Yin, who tells him that he must choose who he loves more (Juliet or Abigail), and that there is no way to save them both.
He particularly praised the red herrings of the episode, including the filmmakers making the audience momentarily believe that Mary and McNabb could be possible Yins.
Kraków also speculated on Juliet's breakdown in the epilogue and its ambiguous nature: "It makes sense that she was scared out of her mind, staring death in the eye and needed a shoulder to cry on (in this case, Det.
Kraków finished the review with the following: Gerald So also praised the episode, but stated that the tone seemed a little too serious compared to the rest of the series.
[3] The episode received an Emmy Award nomination for Outstanding Music Composition For a Series (Original Dramatic Score).
[4] The entire episode was based upon several themes and iconic scenes from Alfred Hitchcock's canon.
The episode follows Shawn and Gus as they, along with Yang (Ally Sheedy) and the rest of the SBPD, attempt to track down and arrest Yin one final time.