It's the middle of the night at the estate of eccentric record producer Ian Blackburn. Blackburn is in his home studio, working on some songs for his pop superstar wife, Chloe (Carmen Electra). An alarm goes off, and Blackburn grabs his pet chimpanzee, Darwin, and runs to his fortified panic room where, moments later, police arrive on the scene and blast their way in. They enter to discover an incredibly bizarre tableau: Blackburn shot dead with Darwin the chimp standing over him, covered in blood and holding a revolver. Stottlemeyer and Disher reluctantly hold Darwin as the prime suspect, but they quickly enlist the help of Monk to determine the guilt or innocence of this most unlikely simian suspect.