David Gitelson, the back-up quarterback for a local professional football team called the Condors, is out partying the night before a big playoff game. While he's in a nightclub, his driver, Shawn Metzger, finds the team's top-secret playbook in the back seat of the Gitelson's limousine. Metzger calls the opposing team's coach and works out a deal.
The next morning, as Gitelson prepares for the game in the locker room, he opens his playbook and immediately knows there's something wrong. He goes to the parking lot, finds Metzger, and accuses him of selling him out. Gitelson threatens to call the police, and the verbal argument becomes physical. Metzger grabs a weapon and strikes Gitelson in the head! Gitelson collapses, dead.
Later, Monk and Captain Stottlemeyer arrive at the stadium. Monk has been invited to watch the game from the press box with Bob Costas (Monk once helped Costas out of a jam), and Monk has brought Stottlemeyer along for some male bonding time. As they walk through the parking lot, they encounter crowds of rowdy tailgaters, including one fan in full makeup who's already passed out in his lounge chair. Monk is appalled. Just as Monk and Stottlemeyer are about to enter the stadium - BOOM!! - a fan's grill explodes into a giant fireball!
Much to Stottlemeyer's chagrin, Monk can't enter the game while there's a potential crime to be solved. Monk and Stottlemeyer go back to the parking lot to talk to Chet Walsh, the fan with the exploding grill. Chet accuses some rival fans of rigging the grill to explode. When Monk and Stottlemeyer go to question the fans, Stottlemeyer recognizes them as some old football buddies from high school. They show Stottlemeyer a speeding ticket they received 35 minutes ago, meaning they couldn't have been around to booby trap the grill.
After much convincing, Monk finally decides to hit the "off-switch" in his brain and accompany Stottlemeyer into the game - that is, until he recognizes a picture of a championship ring on a game program. It's the same ring the "passed-out" tailgater was wearing when they first arrived. They find the tailgater, and Stottlemeyer recognizes him as David Gitelson, who they now realize has been murdered.
Stottlemeyer wants to enter the game and leave the investigation to the proper, on-duty authorities, but Monk can't ignore the case. Exasperated, Stottlemeyer blows up at Monk and leaves to watch the game without him.
Monk, now working the case alone, confronts the limo driver, Metzger, whom Monk believes was responsible for the exploding grill, and possibly more. Unfortunately, Monk doesn't have enough proof to detain Metzger, and Metzger drives away.
Monk then seeks out Chet Walsh, who asked Gitelson for an autograph that morning. The quarterback blew him off while angrily repeating, "It's out of order!" Chet and Monk use Monk's all-access pass to snoop around the stadium. On a TV monitor, Monk sees that the heavily favored Condors are struggling to compete with their opponent. The opposing defensive coach, Brian Binsack, has unexpectedly shut down the Condor offense.
Suddenly, Monk has a breakthrough. He realizes that it was the playbook that was "out of order." Metzger the limo driver stole the playbook in order to photocopy it and sell it to Binsack. When Metzger put the pages back, they were not in the correct order and Gitelson knew something was wrong. Gitelson got killed while confronting Metzger, who disguised Gitelson's dead body to look like a passed-out fan. Metzger saw Chet asking Gitelson for an autograph that morning, and worried that Gitelson might have told Chet about the stolen playbook. Metzger rigged the grill to explode in an effort to kill Chet and make it look like an accident.
Monk and Chet sneak into the opposing team's locker room at half time and grab the stolen playbook. Just as they're about to make off with it, they're spotted and have to make a quick getaway from a team of security guards. Meanwhile, up in the press box, Stottlemeyer's conscience gets the best of him; he says goodbye to Bob Costas and leaves to go find his friend. Along the way, he runs into Chet, who fills him in on the case.
Stottlemeyer catches up to Monk, and they try their best to outrun the guards and Coach Binsack, passing the stolen playbook back and forth. They stay ahead of their pursuers until Monk overthrows the book and it lands just out of Stottlemeyer's reach - and right into the hands of Lt. Disher, who has just arrived with five uniformed officers. Binsack surrenders.
Monk and Stottlemeyer get to relax and watch the rest of the Condor's stunning comeback from the best seats in the house - the press box - along with Bob Costas, who declares the two friends to be the real MVPs of the game.