What could possibly make a cherry pie worth killing for? Monk finds out, with a little help from his long-lost brother Ambrose.

Monk solves a Halloween murder mystery while he and his brother Ambrose wait for their long-lost father to return home.

As Monk and his friends watch a TV news magazine piece on the solution of his hundredth case, he realizes that one of the victims was murdered by a different killer.

Monk pursues the killer of his wife.