Frank and Jonesy are back. This time the case will require all of their talents. Young female passengers are disappearing from luxury cruise ships. After young twin daughters disappear during a family cruise, Frank and Jonesy must go undercover to find out what's happening. The stakes are high and the odds are against them. Will this case prove to be more than they can handle? Luckily, the twins' father, Jim Mason, has special training and associates from his past that will be called upon as the search for the girls escalates. Follow Frank and Jonesy on this ocean-going adventure as they search for the twins and dredge up powerful bad guys from one of their past cases in this latest adventure, Frank Immersed.