Watch Psych: James and Dule's Top 20

James and Dulé's Pick: Leonard "Diddle" Callahan (Demond Dann), a college friend of Gus is chased by armed assailants and when he reaches his apartment building, drops his bike and runs inside. Before the men break in and asphyxiate him Diddle pulls a digital camcorder from his backpack and is able to email out its contents. Shawn and Gus attend Diddle's funeral where Shawn discovers that Gus was in a singing group with Diddle and their other friends Tony (Jaleel White) and Joon (Kenan Thompson), but he has been estranged from them for years and refuses to say why. When Tony and Joon are able to speak to Shawn alone they tell him Diddle was way too careful on his bike to die in an accident. They believe he was murdered, and they hire Shawn to find out what happened.

James and Dulé's Pick: Shawn, Gus, Lassiter, and Woody the coroner wake up in the Psych Office having no recollection of what happened the night before. When a body shows up dead, all leads initially point to our guys as being the culprits, but since they have no idea why they have no memory of this, they conclude that someone must have drugged them. From there, they conduct an investigation using clues and blurred Shawn Vision Flashbacks in order to exonerate themselves as well as find the real killer. Guest Stars: Jessica Lucas, Kurt Fuller, Jeff Hiller.

James and Dulé's Pick: After Lassiter moves into a new condominium building and strange things start happening to him, he is forced to hire Shawn and Gus to figure out what could be causing the supposed paranormal disturbance.

James and Dulé's Pick: When the latest incarnation of American Idol rip-off shows sets up shop at the Arlington Theatre, the requisite cruel British judge (Tim Curry) finds himself in a panic after a series of near-miss attempts on his life. Police protection has been barely sufficient and now he's taking matters into his own hands to ward off his inevitable attacker, hiring Santa Barbara's most reliable psychic detective to protect him.

James' Pick: Juliet and Lassiter meet Gus at a vehicle storage yard in the middle of the night after Gus receives a message from Shawn telling him that he'd solved their case and to meet him there. When Shawn doesn't show up they grow worried especially after Lassiter finds blood on the ground and they realize Shawn's been shot and kidnapped. Lassiter and Henry team up to track him down, while Gus and Juliet retrace the steps of Shawn's latest investigation.

Dulé's Pick: It's Gus' birthday and Shawn gets him the ultimate present. They are both on the VIP list for the fall launch party for Ciao clothing as the modeling team "Black and Tan." Once in, Gus is excited to see his favorite unknown model, Berlinda Desidovicz, and as he goes over to talk to her, Shawn notices one of Ciao's owners, Ciaobella, berate her assistant and throw a green shake onto the ground. Just then, the other owner, Ciaobella's husband Gregor Uwe-Steeb, gets up to give a speech. He starts by saying he did all the designs for the new line, then as he reaches down to adjust the mic stand, he's electrocuted to death.

James' Pick: The favorite to win this year's Regional Spelling Bee passes out under mysterious circumstances in the middle of a word. As Shawn and Gus investigate, the Spellmaster falls over a railing to his death. Lassiter thinks it's obviously an accident but Shawn is sure it's murder.

Dulé's Pick: Two former cops come out of retirement to help Shawn and Gus solve the murder of a former police chief.

James' Pick: Shawn and Gus receive a mysterious email inviting them to the Cinnamon Festival in Dual Spires, a quirky small town nearly invisible on a map. They arrive to find themselves embroiled in the mystery of the drowning death of a teenage girl -- who was declared dead under similar circumstances seven years ago in Santa Barbara. Sherilynn Fenn, Sheryl Lee, Dana Ashbrook, Robyn Lively, Lenny Von Dohlen and Catherine Coulson guest star.

Dulé's Pick: Juliet gets a visit from her estranged father, a charming con man who wants to mend his broken relationship with his daughter, but when the opportunity to pull off a dream con is presented to him, his decision to stay on the right side of the law becomes more complicated. Guest Star: William Shatner.

James' Pick: Juliet goes to the train station to meet Scott Seaver (Josh Braaten), her college boyfriend, to make good on the pact they made to meet there exactly seven years after saying goodbye. When Scott never shows up Juliet grows curious and uses police resources to track him down, but Vick puts a stop to that before she can find anything. Juliet enlists the help of Gus and asks him to keep Shawn out of it because of their romantic history. Gus' cover is quickly blown when Shawn figures out he is doing something behind his back and Shawn joins the investigation as well.

Dulé's Pick: Lassiter's new relationship with a mysterious and beautiful woman is placed in jeopardy when Shawn and Gus are convinced she is a murderer -- the same murderer responsible for the blood-drained body SBPD is investigating. Guest Stars: Kristy Swanson, Corey Feldman.

James' Pick: When Shawn arrives late to meet Gus at a screening of Psycho, he has to squeeze down the row past other theatergoers to take his seat. On their way out of the theater, they are surprised to meet Mary Lightly (Jimmi Simpson), who helped them track serial killer Mr. Yang. Mary takes them to a diner, where they discuss Yang's new book that has just been released and Mary points out that, according to the book, Yang could not have been working alone. Shawn and Gus don't believe it, and leave the diner - and the Yang case - behind. Later they are called to a crime scene to find the waitress from the diner murdered and her body arranged into a Yin/Yang symbol.

Dulé's Pick: When a woman is found dead with a bottle of pills that are lab trial samples, Lassiter and Gus, who are taking the same tap class, team up to dance their way to catching a murderer.

James' Pick: Shawn and Gus are hired by a childhood friend to find missing camp counselor Annie, who disappeared near their old sleep away campgrounds. Upon their arrival, spooky activity abounds and they must uncover if the dark past of the abandoned camp has come back to life. And, oh yeah, Justine Bateman guest stars as Lassiter's estranged wife Victoria!

Dulé's Pick: The Yin Yang Killer, a serial killer who was active when Henry was a cop then went silent, is back and wants to toy with the department again, this time singling out Shawn as his primary playmate. Mr. Yang challenges the cops with the opportunity to save his victims by solving his riddles. Yang has just sent them another one, along with a stopwatch. They have an hour and ten minutes to solve the riddle and save his latest victim. Cybill Shepherd and Rachael Leigh Cook reprise their roles in the season finale ... and watch for a secret celebrity in the role of Mr. Yang!

James' Pick: The police have called Shawn and Gus down to the television studio. There has been a murder on the set of the telenovela "Explosion Gigantesca de Romance," Gus' favorite soap opera. But when they get to the set, Lassiter says Juliet jumped the gun calling them and the case is open and shut, in fact the whole thing was caught on tape. One of the actors, Jorge Gama-Lobo stabbed the victim during one of the scenes. But Jorge insists someone switched the prop knife for a real one without his knowledge.

Dulé's Pick: Alone in a bar, Shawn spots Lassiter at a table, drinking heavily, marking a sad anniversary. Lassiter invites Shawn over and proceeds to pour his heart out, confessing that Shawn's skills astound him. While Lassiter doesn't believe he's psychic, Shawn somehow guarantees an arrest, whereas Lassiter, who used to be a great cop, now can't even solve the murder of a local astronomer. Everyone thinks Bryant Vallery died of natural causes, but the guy was relatively young and lived a healthy lifestyle. Lassiter tells Shawn that he knows there's more to it but can't prove it ...

James' Pick: On Halloween night in 1985, Shawn and Gus witness a troubled girl throw herself from her window at the Wispy Sunny Pines mental institution. From that moment on, "Scary Sherry" has haunted the halls of the now abandoned facility where we find a girl, Doreen, being chased by a ghost before falling through the same window to her death below. In the Psych office, Juliet comes to Shawn and Gus for help. She is undercover at the Beta Kappa Theta sorority, of which Doreen was a pledge. The going theory is that Doreen killed herself in a copycat of Sherry's original suicide but Juliet thinks there is more to the story.

Dulé's Pick: After Shawn Spencer convinces the police he is psychic in order to get out of an aiding and abetting charge, Interim Police Chief Vick hires him to help out on a high-profile kidnapping case, being led by Detective Lassiter. Shawn brings in his best friend Gus to help him find the missing man and they soon realize this kidnapping isn't what it seems to be. Now he must "psychically" lead the cops in the right direction, which ends up taking a sudden and unexpected turn.