Mr. Monk and the Other Detective

S4, E1: Harold Gumbal robs his own jewelry store and delivers the loot to two thugs who have taken his dog hostage. When a security guard shows up, one of the thugs panics and kills him. With Gumbal now a witness to the murder, the shooter turns to Gumbal and kills him, too, in cold blood. Monk is called in to investigate. Before he can make any progress, a disheveled, second-rate detective named Marty Eels (Jason Alexander) shows up. But today, Marty's detective skills are far from second rate. In fact, he's amazing. He's even better than Monk. He seems to be solving the case by magic. Monk, meanwhile, is convinced that Marty Eels is cheating.