Monk and Sharona are called to the home of Susan Molloy, the ex-wife of popular TV star Brad Terry. Once there, they learn that Susan was stabbed inside the house while Brad was out front dealing with the paparazzi - that is, until everyone heard Susan's screams. The evidence points to a break in, but Monk thinks otherwise.
Monk and Sharona pay a visit to the set of Brad's hit TV show, "Crime Lab S.F." There, they learn that the show is celebrating its 100th episode, which in turn means a VERY big payday for Brad - a payday he's likely unwilling to share with his ex. Monk thinks he's got him, but when the TV star volunteers for a lie detector test and passes with flying colors, it's Monk whose been had.
Following his little victory over Monk, Brad intentionally invites Sharona, Captain Stottlemeyer, and Disher - but not Monk - to the show's cast party, leaving Monk alone and dejected. At the party, things go from strange to even stranger when an obsessed fan of the show, Marci Maven, crashes the party and urgently tries to talk to Brad. Stottlemeyer and Disher step in when she confesses to killing Brad's wife.
The next day at the station, Stottlemeyer calls in Monk to hear Marci's story, but Monk just doesn't buy it. Despite her confession, and to the chagrin of everyone, Monk continues to probe Marci, and he eventually discovers that Susan Molloy was an actress years earlier, starring in one B horror flick. That's when it hits him: the screams coming from inside the house were in fact Susan Molloy's... but they were 15 years old! Brad had manipulated the sound on one of Susan's workout tapes with Susan's own screams from her old movie. When the tape played, the screams attracted the attention of the press outside, and Brad appeared to run in to check on her - all the while giving him the time to kill her himself.
It was the perfect plan, but the TV star made one fatal mistake... he didn't count on Adrian Monk.