When forensic pathologist Dr. Harper Quinn finally takes a real vacation, she boards the Miami-to-Bahamas luxury liner MV Victoria determined to sleep in, sip cold brew on deck, and ignore anything that looks like a crime scene. The ocean has other plans. On the third night—while a jazz quartet croons standards in a small theater—Harper is yanked from bed by two anxious ship security officers: Nate Hill, a sharp but green team lead with something to prove, and Mina Park, a rookie whose courage outpaces her training. In a sea-view cabin slick with blood, a wealthy insurance executive lies with his throat cut. No signs of struggle. No usable prints. A locked door that should only open to two keycards. By dawn, a second man is found dead in a penthouse suite—killed the same way, but with a grotesque twist that screams personal. The Victoria can’t turn back without detonating lawsuits and headlines, so the captain seals the scenes, chills the bodies, and keeps the party going. Passengers sunbathe. Kids watch movies under the stars. The midnight buffet still rolls out crab legs and key lime pie—while a killer moves deck to deck, blending into the crowd. Harper reads what the sea refuses to hide: tampered keycards, a smartwatch that preserves a dying heartbeat, a bucket hastily used to revive the already dead, and a pattern that feels wrong—too tidy—until it snaps into place. This isn’t random. It isn’t robbery. It’s an offshore pact forged by rage: a cold-blooded “exchange” in which spouses kill each other’s partners and walk away with airtight alibis. Only this time there are three women in the pact… and someone has already broken the rules. With the ship due to dock at Fort Lauderdale at sunrise, Harper races a clock measured in nautical miles and gossiping group chats. She’ll have to outthink a charming tech bro who lies with a smile, a cruise GM who knows more than he’ll admit, and a grieving widow who appears too immaculate. Because on a floating city where the walls are thin, the cameras are scarce, and the drinks are strong, the line between witness and suspect is one wrong turn down a service stairwell. Sunset brings music. Midnight brings the red wake.