No one likes to come home to a mess, least of all Adrian Monk and Natalie. But when they return to San Francisco from an extended stay working as cops in New Jersey, Natalie discovers somebody has been sleeping in her bed. But they're not asleep, she is dead. If that isn't bad enough, investigators find marked money from a Federal sting operation stuffed under Natalie's mattress. Now her life is a real mess and she needs Monk's help to clean it up.