Sidney Teal appears to have it all - his own software company, billions of dollars, a beautiful wife, and a beautiful home. But all is not as it seems. One night, Sidney bids good night to his wife and servants, dons a set of kneepads, and gets in his car. He then drives to a movie theater and waits in the shadows. A couple emerges from the theater, and when they pass, Sidney Teal leaps out with a knife, snarling "Give me your wallet! Don't be a hero!" But Teal picked the wrong couple to mug: the man, Archie Modine, suddenly pulls a gun and shoots the billionaire dead.
Meanwhile, Monk is having problems of his own. Simply put, he's flat broke. He can't even afford to pay Sharona. Sharona is threatening to quit if Monk misses one more paycheck, but fortunately for Monk, their argument is broken up by a phone call from Stottlemeyer. Due to the high-profile nature of the Teal case, Stottlemeyer wants to bring Monk in to help investigate.
Right away, Monk has issues with the crime scene. What kind of mugger would don a pair of kneepads before robbing someone? It doesn't make sense. Feeling uneasy about the whole case, Monk meets with Sidney Teal's widow. She talks about how her husband was going through a midlife crisis and was recently trying daredevil activities like bungee jumping and skydiving. But Monk's subsequent interview with Teal's chauffeur discredits her story. The chauffer describes Teal as "a pussycat" who was too gentle to ever even fire a gun.
Eventually, Monk makes a key deduction: Teal and Modine were in the same fraternity. Sharona then discovers (in the pages of Teal's biography) that both men were involved in a similar incident years before. That's all Monk needs to solve the case.
As it turns out, Sidney Teal had no intention of robbing the couple. He was merely playing a part in an elaborate ruse to impress Modine's date. Teal was to jump from the shadows and startle the lovers, giving Modine the opportunity to play the hero. But Modine had something else in mind: his plan was to dispose of the billionaire whose wife he was having a secret affair with by making it look like self-defense. It was a perfect plan that would have gone off without a hitch... if not for Adrian Monk.