01E13 - Mr. Monk and the Airplane

Thinking that he's just accompanying Sharona to the airport to pick up her aunt, Monk discovers to his dismay that she's the one making the flight. The choice between being on his own without Sharona or flying cross-country to New Jersey is a tough one, but he overcomes his fears and boards the plane. After annoying the passengers and crew with his first-time-flier questions, he becomes even more unsettled after small anomalies convince him that the Frenchman sitting across the aisle has murdered his wife and the woman accompanying him is an impostor. He calls Captain Stottlemeyer only to find that it's the captain's day off but manages to persuade Lt. Disher to search the airport for a body. With on-and-off help from Sharona (who would rather be "helping" Tim Daly decide whether to accept a role in an upcoming film) and from the extension cord salesman in the seat next to him, Monk tries to provide the evidence Disher needs to order the arrest. Meanwhile another murder is committed while Monk is trapped in the bathroom. Sharona rescues him, but the co-pilot refuses to believe his story and orders him back to his seat. The angry flight attendant (played by Tony Shalhoub's wife, Brooke Adams) disables the call button and destroys a piece of key evidence, but Monk still has the phone to call Disher, and the race is on to find the body before the murderous couple board their plane for Paris.