From the introduction:
A supernatural murder, witnessed by Patrick Star and perpetrated by Gary Goyle, New York-based gargoyle on holiday, interrupted Bikini Bottom's relative calm and quiet. In exchange for his life, Patrick Star, a dim-witted pink starfish who lives under a rock, promised to keep the murder secret. Unfortunately for and unknown to him, the Gargoyle murdered one of Patrick's best friends and doppelganged into him. Watch out Patrick, you better keep your mouth shut.