Natalie, trying to give her and Monk's detective business a boost, takes the advice of a book expert working with them on the latest case and takes a berth on a cruise ship that hosts a business seminar. Right off the bat, she hits it off with activity director Mariah Linkstetter, and finds out that the young woman is hiding a secret that could cost her everything. When Mariah turns up dead in the water, can Monk and Natalie get to the bottom of what really happened to her?
This book contains examples of the following tropes:
- Afraid of Clowns: Monk's coulrophobia becomes the subject of a gag when one small-business owner sends out a flyer for fundates.com that has two clowns kissing. Between the clowns and the passionate display of affection, it's enough to make Natalie rush to intercept the flyer. However, she discovers that the last major case, which involved clowns, served as immersion therapy and he doesn't really care.
- The Alcoholic: Darby McGinnis is seldom seen sober. This bothers Monk, who winds up having to room with him for a little while and becomes a plot point later on in the book.
- A Deadly Affair: Mariah and Captain Sheffield were seeing one another behind Mrs. Sheffield's back, and Mariah became pregnant. Mrs. Sheffield's family owned the boating company, so the captain couldn't run the risk of his wife finding out. He set up Mariah's murder to look like an accident.
- Didn't Think This Through: The only term that can really be used to describe creating a dating website for the famously non-technology using Amish.
- Let Off by the Detective: Monk and Natalie decide to let the four women go un-prosecuted as long as they agree to abandon their murder plot against Darby McGinnis. It becomes a problem because Mrs. Sheffield, who hired Monk and Natalie to get to the bottom of the mysterious accidents on board, isn't happy with the vague statements Natalie can give her about that part of the investigation.
- Make It Look Like an Accident:
- Captain Sheffield bludgeons Mariah and then puts her on the anchor chain so that it will look like she slipped and fell overboard rather than being murdered. He tries the same thing with Monk at the end of the book.
- The four women trying to get revenge on Darby McGinnis cause a number of "accidents" around the ship, hoping one of them will kill him. Natalie scolds them for this, pointing out that a whole lot of innocent people could have gotten hurt in the process.
- Named After Someone Famous: Mariah Linkstetter got her name because her mother listened to Mariah Carey a lot while she was pregnant with her.
- Too Dumb to Live: Natalie goes to a support group for struggling businesses, and one of them is the owner of a site called AmishMingle.com. Natalie notes that it's no wonder his site is struggling to get more than a couple customers; it's an incredibly useless idea to create an online dating service for the world’s Amish population, when the Amish don't even believe in using electricity, much less the Internet or Wi-Fi.
