Nancy, George, and Bess are off to Fort Lauderdale for spring break. Bess can't wait to hit the beach and check out the hot guys, but Nancy promised her friend Kim's mom that she would check on the girl. Kim was supposed to come home the week before but called at the last minute to say she wanted to stay an extra week. And the hotel actually had a room for her during the busiest time of the year?
Bess and George immediately head to the beach, while Nancy goes to Kim's room. She hears her talking to someone on the phone in a panic and agreeing to meet them right away. Kim rushes out of her room, sees Nancy, and agrees to talk to her later, much later before rushing off. Nancy runs to follow her, loses her sandal, and when she catches up, she sees a car come out of nowhere and hit Kim head on.
Though there were lots of people around, everyone swears they saw nothing. The cops who arrive say it's because most of them are illegal aliens and too afraid to come forward. She also sees a guy with dark hair staring intently at Kim who runs away once she notices him. While riding to the hospital with her friend, Kim mumbles something about Rosita before passing out.
Kim's mom comes down to Florida, and Nancy visits Kim's room. Someone catches her trying to break in and lets himself in with a key, claiming he's a maintenance man. When she comes back later, the room is completely ransacked. The only thing she finds is a strip of photo booth photographs that show Kim with a dark haired woman she assumes is Rosita. When someone sneaks into the room, she hides herself in the closet, and as he leaves, she realizes it's the dark haired guy from the street before.
After finally catching up to her friends, she finds Bess infatuated with a hot blond named Dirk. He and Bess seem in luv until he hears Nancy talking about Kim. He suddenly announces that he's a mystery buff and that he wants to help her. After ditching Bess and claiming he has something that can help her, he cons Nancy into wind surfing with him the next day. Needless to say, Bess is less than happy.
Once the next day arrives, Nancy learns that Dirk knows absolutely nothing and just wanted to spend some time with her. Even though she's initially made at him, she still takes a wind surfing lesson, which ends when one of the poles hits her in the head. While bobbing in the water and waiting for him to come back with the boat, a woman in a larger boat stops and picks her up. The woman is Lila, Dirk's boss in a party boat company.
Nancy eventually finds out that the dark haired guy is a lifeguard named Ricardo. He acts super cold around her every time they meet, and after he hooks up with Bess, he takes off running when he sees Nancy. She later discovers him with the dark haired woman from the pictures and gives chase. The woman isn't Rosita, she's a woman named Maria who is an illegal alien. Kim met her through Ricardo and agreed to let this complete stranger live in her hotel room.
As the investigation heats up, Maria goes missing and Ricardo winds up dead with his body washing up on the beach. Nancy gets too close and winds up getting hit over the head for the 900th time. She waked up tied to the pier on the beach with the tide coming in and the water getting higher. A little struggling leads to her slipping the binds on her feet, and she uses the pier to break the binds on her hands.
She's so tired and sore that when she gets back to the hotel, she passes out in Bess's bed. The other girls are shocked when they see her appearance and agree to help her with anything she needs. Then George lets it slip that the name of Lila's boat is the Rosita and Nancy puts it all together. Lila's family owns a citrus grove, which the book never mentioned before. She helps immigrants sneak into the country on her boat and then forces them to work in the grove or she'll call the cops on them. They also find out that Kim woke up in the hospital and that she somehow disappeared.
The girls dress up in disguises and sneak onto the boat to look for Kim and Maria. Luckily, Lila planned a huge party on a nearby island, which makes things easier. One of Lila's guys grabs Nancy, drags her downstairs, and gives her to Lila, who takes her to a hidden room and tosses her inside. There, she finds Bess, George, Kim, and Maria waiting for her.
Dirk then shows up with a gun, and Bess throws herself at him, whining about how much she likes him and how they should run away together. Nancy figures out it's a trick, kicks the gun out of his hands, and slams his head into a wall until he passes out. Oh my. When the boat reaches the island, they make their escape but some of Lila's guys give chase.
The girls split up, and Nancy ends up with one of the largest guys chasing her across the beach. Dirk suddenly shows up, knocks the guy out, and helps her find the other girls. They manage to take one of the smaller boats that Lila used to transport passengers from the Rosita to the island. Dirk then reveals that he is an undercover cop investigating Lila on suspicion of smuggling people into the country. He wanted to tell Nancy but wasn't sure he could trust her.
Lila uses the larger and faster boat to catch up with them, and one of her goons starts shooting. Dirk shoots back, but can't drive and shoot at the same time, so he gives the wheel to Nancy. Lila keeps maneuvering the boat to stop them from getting close to the shore. Nancy gets the brilliant idea to drive over a sandbar, which sends the boat flying through the air past Lila's boat. Lila then gets stuck on the sandbar herself.
Wrap up time! Dirk arrests Lila and her goons. Kim's mom suddenly has connections in Florida and has a friend who agrees to sponsor Maria to let her stay in the country. We never learn what happens to all the other immigrants. Dirk gets close to Nancy and eventually kisses her, only for her to remind him that they left a bunch of college kids on the island the night before. The book ends with him rushing off to help them.
*Nancy mentions at the very beginning that she's oh so happy with Ned, but then kisses Dirk back at the end. Bad girl!
*Bess who is always described as slightly overweight, even in this book, wears a tiny hot pink bikini at one point and a red string bikini later. All the guys in town keep drooling over her and following her around too.
*Nancy steps on a man of war, which causes her foot to swell up on the beach. Ricardo sees and completely ignores her. Pretty sure he'd lose his job over that. The doctor then gives her a magic salve, and she's back to normal the next day without even a limp.
*Ricardo kept running away from her because he was worried she'd find out about his secret. He was an immigrant using a fake ID card. Kim and Ricardo also had a short romance.
*Dirk ditches Bess for Nancy in the beginning but later comes back and starts seeing Bess again. In the end, he kisses Nancy and once again ignores Bess.
*I know I read this book as a kid because I totally remember the cover! It kind of makes me sad that if they ever bring these books up to the modern day, they'll make her super skinny. She's actually a little muscular/athletic on this cover.