Professor Cait Morgan and Bud Anderson have finally said 'I do'. To celebrate, they set sail on a romantic Hawaiian honeymoon cruise and, for nearly two weeks, the mystery solving newlyweds are worry-free. But then a man drops dead in the games room right in front of them and Cait and Bud can't help but lend their expertise. To the others in the games room, the sudden death of Tommy Trussler--the ship's onboard card-game tutor--appears to have been from natural causes. But the professor suspects something much more sinister. With only two days left at sea--and thousands of possible suspects--the head of security is eager to solve the case and invites Cait and Bud to aid in the investigation. But the unique circumstances of an at-sea investigation mean their involvement cannot be official, and Cait must lean on her charm to conduct her own covert interviews.