Shawn and Gus find themselves caught between two rival Chinese Triad families as they search for one of the leader's abducted daughter. Meanwhile, Shawn's father Henry joins the police department in charge of the "consultants" - Shawn and Gus. Juliet also deals with the lingering traumatic effects of her kidnapping in last season's finale.
Shawn and Gus help on a case involving a seemingly alien abduction. They ask their childhood friend Dennis to help them since he believes in aliens. The three determine it is not aliens so much as a devious corporate man.
Shawn and Gus return to Vancouver to visit their old nemesis, Despereaux, in prison at the felon's request, who then uses them to escape. While planning the perfect theft, Despereaux is set up for murder and must once again work with Shawn and Gus to prove his innocence.
While on the haunted house ride at Santa Barbara's Scare Fest, Shawn and Gus witness a murder and are soon led to believe the person who committed it is the ghost of a man who fell to his death at Scare Fest 13 years ago.
After messing up on a case, Shawn wonders what life would have been like for his loved ones without him in their lives. He is shown by an elf in a dream. He goes through his loved ones lives and makes many surprising discoveries about them... and himself.
A woman tells the police she was kidnapped by Yin. They do not believe her but Shawn does. When she is missing again, Shawn and Gus think she has been kidnapped again. Yang is released from the psychiatric prison to help find him.