"Let's Get Hairy" is an episode of the dramedy Psych which makes suitable viewing for Halloween. It was originally aired in the US in 2009, during Season 4. Despite being broadcast during October (October 9 specifically), it was not actually the Psych episode to air closest to Halloween that year; instead that honor falls on the episode that aired next, Shawn Takes a Shot in the Dark which aired on October 16 of that year.
Created by Steve Franks and broadcast on the USA Network, Psych is an American detective comedy-drama (also known as a "dramedy") which follows Shawn Spencer (played by Jame Roday), a young crime consultant who pretends to have psychic powers, when instead he is simply using a heightened sense of observational skills and detective instincts above the rest of the Santa Barbara Police Department. He chose to pretend to be a psychic after numerous tips he called in to the police department made them suspicious as to his overt knowledge of the crimes. Shawn is followed around by his best friend and reluctant partner, Burton "Gus" Guster (played by Dulé Hill), as well as his father, Henry Spencer (played by Corbin Bernsen) who is a retired member of the police force, who also taught Spencer to be a super sleuth.
A man named Stewart Gimbley comes into Shawn and Gus's Psych office. He tells them that he needs their help because he is a werewolf and is dangerous to society. He tells them how he woke up that morning undressed, with a dead lamb and with no memory of the previous night. He asks Shawn and Gus to tie him to a chair, so he cannot escape. At first, Shawn and Gus are reluctant to do this but, when they are offered triple pay, they agree to do this, saying it is easy money. Stewart gives them a gun for their protection. Shawn and Gus pay no attention to him that night and soon drift off. When they wake up, Stewart is gone, the window is shattered and a string of hair is dangling from the shattered window. Outside, the two notice a full moon.
The next day, Stewart wakes up in the middle of the woods. Once again, he is naked, and is lying next to two dead hunters who have wolf scratches on them.
Meanwhile. Shawn and Gus go to the police station, looking for help in tracking Stewart. Head detective Carlton Lassiter tells Shawn that Stewart came to them the previous day, but they did not believe him when he said he was a werewolf. Lassiter says there were two hunters killed and Stewart is the main suspect. He tells them that Stewart has a sister named Willow, who may be able to help track him.
Shawn and Gus go to Willow, who tells them that Stewart has been bitten by a wolf recently. Shawn notices a picture of Stewart, and a group of other people. Willow tells Shawn that they are his theropy group and that they got together for his birthday.
Back at the Psych office, Shawn looks through Stewart's overnight bag. He discovers medication, which Gus (using his pharmaceutiical knowledge) identifies as Haloperidol, which is used for schizophrenia and aggression. They decide to see his psychiatrist, Dr. Tucker, but his secretary, Myrtle, refuses to let them in. However, while she is distracted for a minute, Shawn takes a picture of information on her computer with Gus's phone. Myrtle is then seen walking a woman out. Shawn thinks that she looks familiar but cannot remember where he knows her from. Suddenly, he remembers that she is the bartender in Stewart's therapy picture. He decides to question her, in her bar, about what she knows about Stewart. The young woman introduces herself as Polexia, and hints that no one is ever going to see Dr. Tucker again.
When Shawn and Gus return to Psych, they find Stewart hiding in the closet. He tells them that he plans on turning himself in, so he will not cause any more damage. However, Shawn tells him that he believes him to be innocent. He asks Stewart if he knows Polexia. He replies that Polexia used to dominate their group sessions until she threatened Tucker. Now she only does one-on-ones with him. Shawn begins to believe that Polexia set Stewart up and is the real murderer.
Shawn and Gus ask Willow to stay with Stewart for the night (which is another full moon), while they look for proof the Polexia is the murderer. They sneak into Dr. Tucker's office, and check for her files. However, her file is missing. When they look at Stewart's files, they notice that the doctor switched his prescription for horse tranquilizers. They also see stuffed animals and ladies' underwear. Shawn tells Gus that he has solved the case. He calls Lassiter and Juliet O'Hara and tells them to meet him at Willow's. However, at Willow's, she reveals that Dr. Tucker took him.
Shawn, Gus, Lassiter, Juliet and Willow, find Dr. Tucker in the woods with Polexia. Shawn reveals what happened. Polexia was having an affair with Tucker. She threatened to expose him, which would ruin his practice (as it is inappropriate for a doctor to be sleeping with his or her patients) as well as his marriage. Tucker was going to kill Polexia and pin it on Stewart, using the claws and teeth of a stuffed wolf, as he did with the lamb and the hunters, making it seem like a werewolf did it. Knowing Stewart would believe that he was a werewolf, he would take the blame for the deaths and Tucker would get away with the murders. Dr. Tucker is upset that his plan has been discovered and is arrested.