In Season 5, Shawn (James Roday) and Gus (Dulé Hill) cross paths once again with figures from old cases: art thief Despereaux (Cary Elwes); Father Westley (Ray Wise), in a notable "Twin Peaks" homage episode that includes guest appearances from the original cast; and the always scheming Yin and Yang. Juliet (Maggie Lawson), meanwhile, starts dating a handsome criminal profiler (Nestor Carbonell), and Henry (Corbin Bernsen) becomes the head of the police consultants. Timothy Omundson and Kirsten Nelson also star.

Creator Steve Franks' comedic entry into the crime-solving genre follows the investigative efforts of fake psychic Shawn Spencer (James Roday) and his childhood pal and sidekick Burton "Gus" Guster (Dulé Hill). Though Shawn has top-notch observational skills and the keen instincts necessary to become a detective, he also has a free-spirited, goofy side that prevents him from pursuing a serious career in police work, much to the chagrin of his father Henry (Corbin Bernsen). A former detective, Henry honed his son's talents at a young age and is constantly frustrated by Shawn's carefree view of adult life. Henry's former colleague Interim Chief Karen Vick (Kirsten Nelson), however, sees Shawn as an asset for solving tough cases, even though she's skeptical of his alleged psychic ability, a lie Shawn manufactured after he gave the police a tip that was so accurate he became a suspect.

The fourth season of Psych continues to follow the investigative efforts of fake psychic Shawn Spencer (James Roday) and his childhood pal and sidekick Burton "Gus" Guster (Dulé Hill) at their own highly unique detective agency.