Ainsley Waylon, people watcher extraordinaire, is stuck in a rut. She's taken all of her pre-requisite classes for her undergrad degree but can't seem to pick a career that she'd be happy with. To help her relax and take a step back from everything, her brother Harper books a cruise for the two of them.

When Ainsley and Harper meet meet Detective Joelle Matthias during breakfast one morning, Harper is thrilled that his sister is taking an interest in interacting with something besides a book. Though the two women hit it off immediately, the murder of another guest draws both of them into the center of the action.

With a ship full of suspects, Ainsley's eye for detail leads Joelle to ask for her help with the investigation, but can they follow the clues to solve the case before the ship docks and lets a murderer go free?