Nancy, Bess, and George are once again off to solve a mystery, this time on an Alaskan cruise ship. See, Nancy is friends with this girl Becca. Becca works for a brand new cruise line that has celebrities going on cruises with people. Some weird and strange crap happened that led to their first celeb dropping out, so she asks Nancy to come aboard and find out who is behind everything. The girls have to solve the mystery while keeping their snooping a secret from Alan, Bess's new boyfriend.
Not long after getting on the ship, someone screams. They find a “dead body” in a “bloody pool,” which actually turns out to be a mannequin and powdered drink mix that someone threw in the water. A couple on their honeymoon, Vince and Lacey, seem particularly upset. They also meet Tobias, a rude little kid who moans and whines about how he doesn't want to be there and how cruises suck.
Becca is on hand to calm everyone down and to slip a message to Nancy about them meeting up later. Before that can happen though, Nancy's main suitcase goes missing. Her butler, and yes, her room has a butler and TWO maids, finds it in a completely different room. Someone slipped a note inside that warned her to stay out of things.
At dinner, the girls meet the ABC ladies. These three older ladies each have a name that starts with one of those letters and go on cruise ships together all the time. They point out how familiar newlywed Lacey looks and how she looks just like a woman they interacted with on a different cruise ship.
Nancy quickly makes a list of suspects. Hori, the guy in charge of the kids' club, is a suspect because he's around when stuff happens. Scott, another worker, is a suspect because he's also around when stuff happens. She also suspects Tobias, the poor kid, after someone discovers a huge spider in the buffet, which turns out to be his pet that he brought from home. Also on the list is Iris, one of the maid, because Nancy spotted her coming out of a room that she wasn't supposed to clean.
Other than the mannequin thing and the spider, not a whole lot happens. They go mini golfing, which ends when a giant bear on the course falls on Nancy after Bess leans on it. An inspection finds that someone removed the bolts holding it to the ground. Though Nancy wants to do more sleuthing on their next excursion, Alan reveals that he already signed them up for a ton of activities.
Seeing Scott act a little shifty, Nancy follows him around town and sees him giving some guy money. He tells her that he's a poker player and needed to pay back a friend, but he also begs her not to tell anyone on the ship what she saw. While making her way back to the ship, someone hits her from behind and pushes her into freezing water. Since she's Nancy, she manages to escape and find a way back to the ship.
To get rid of Alan, who is literally always hanging around, Nancy makes a comment about how she really wanted to get some postcards while in town. Being a gracious gentleman, Alan offers to run back and get some for her. Nancy then runs into the newlyweds who tell her how they spent the day at the gym. Suspecting them of lying, she goes to the gym and learns they weren't there.
This somehow helps her put everything together in her mind. She calls the captain and Becca to meet her. They find the couple filling bottles of sunscreen with poison and catch them in the act. Turns out that they both worked for a rival cruise company that offered them a big payout to sabotage this cruise. The captain takes them both into custody, though they do claim that they didn't do all the bad stuff.
Becca hears more bad news: someone from the ship stole a ton of jewelry. Nancy knows it wasn't the “newlyweds” because they were doing other stuff at the time. The book ends with her thinking about how they didn't solve all the mysteries of the ship but how they have time because they have more travel plans ahead of them.
*To cover up why they're really there, Becca made it seem like they won a cruise and gave them the ultra fancy Hollywood Suite. When Alan heard the suite had four bedrooms, he kind of invited himself along. It would annoy the crap out of me, but Bess acts like it's totally cool and no one else cares.
*Bess and Alan have only been dating a few weeks, which makes things even weirder. Who takes some guy they just met on a cruise that lasts for multiple weeks?
*Bess makes George borrow a dress to go to the fancy dining room, and George complains the whole time. She's even more angry when she finds out there are dining rooms on the ship that let you wear whatever you want.
*It seems a little weird to me that Becca is Nancy's friend because she's described as several years older but is older enough that she graduated from college and has a full-time job.
*Nancy says that Alan is a few years older than them, but he's only a sophomore in college.
*The whole Alan thing really annoys me. In what world is it cool for you to invite your new boyfriend on vacation with you and your friends, or even agree when he suggests he come along? The fact that he completely changed their travel plans and signed them up for a bunch of stuff is annoying too.
*This is the first time that I read any of the Nancy Drew Diaries series, and I'm not sure how I feel about it. I'm not a big fan of cliffhanger books like this one, where you don't realize it's a continuing story until you get to the end.