Arson Inspector Morgan Conrad has come to the police for help. A building burned down under what she believes is suspicious circumstances but, since the fire superficially appears to be accidental, she is getting no support from her department. Shawn and Gus, who used to want to be firemen when they grew up, volunteer their assistance. Shawn, Gus, Lassiter and Juliet go with Morgan to the scene where they run into her boss, Army Johnson, who tells them that the building had no fire insurance, so there is no motive for arson. Plus, arson is so rare, he hasn't seen a case since way back to his firefighting days. But Morgan counters that one of the fireman on the scene reported smelling something sweet, a sign of an accelerant. As Shawn looks around the scene, he notices that one of the walls lacks insulation. He grabs a pipe and smashes it into the wall, revealing a blackened skeleton hidden inside. Now it's not just arson, it's murder.

Shawn and Gus are at the police station when the cops bring in Ryan Bainsworth for murder. Ryan's hands are covered in blood but he insists he's innocent. Juliet tells them they've arrested Lyin' Ryan, a notorious compulsive liar who has called in countless tips only to lead the cops on wild goose chases. It looks like this time Ryan actually committed a crime himself. Shawn and Gus follow Juliet to the observation room, where they listen to Lassiter questioning Ryan on the murder of his super in his apartment. Ryan claims that he asked his super to fix his disposal after clogging it with cinnamon sticks and lemon wedges from a marinade and to check the pipes because the polarity is off and the water drains counterclockwise. When he got home he found his super bloody on the floor and tried to revive him. He insists the real culprits are actually two hired assassins. He tells Lassiter that the night before, he was in a restaurant eating special twice-fried fries, when a car crashed through a window across the street. As he turned to look, he overheard a guy with curly q's on his face talking to his companion about killing someone with his belt buckle. Obviously, the assassins realized he overheard them, came to kill him and got his super instead. When Lassiter, who isn't buying any of this, asks how they would know how to find him, Ryan admits he put up flyers around the neighborhood in an attempt to find them and stop them. The cops are incredulous but Ryan is desperate, saying that if they don't believe him someone else is going to die. Fortunately, Shawn sees that this time Lyin' Ryan is telling the truth.