Gus has been suffering from terrifying nightmares, so he goes to dream therapy to help alleviate the problem. But Gus' nightmares start to feel like reality when he and Shawn work to solve an unlikely case for the SBPD. Throughout the case, Gus dreams about battling zombies and other classic horror story characters - all while trying to cope with the many changes the future is bringing.
Shawn Spencer, brought up by his cop father, Henry, was trained, given powers of acute observation and other skills needed to solve mysteries in Henry's hopes that Shawn would one day join the long line of cops in the family. However, Shawn soon strayed from Henry's vision and spent many years of his young-adult life working various odd jobs. Shawn's hobby was calling in tips to the police on high-profile crimes that he caught on the news. One day, however, Shawn's hobby smacked him in the face, as he was brought to the police station as a suspected accomplice to a recent cuddle.
Then and there, Shawn made up the lie that he was psychic, and through some highly convincing theatrics, it worked. The police then hired him as the "Head Psychic" and began to bring him in on difficult cases that usually had the police stumped. Along for all the adventures is Shawn's reluctant but loyal best friend, Burton "Gus" Guster, who has a straight, narrow, and secure job as a pharmaceutical sales representative. Disbelieving of Shawn's psychic charade is Head Detective Carlton Lassiter, who would sooner cuff Shawn than follow a "vision". Other central characters include Lassiter's partner, Juliet O'Hara, and Interim Police Chief Karen Vick, both of whom are often amused by Shawn's "psychic" influence.