Agatha always saves the day in style! It's finally vacation time, and the Mistery cousins are enjoying a cruise on a luxurious transatlantic ship called the King Arthur. Unfortunately, crime never takes a rest! Agatha and her friends get caught up in a spy conspiracy, in which they must retrieve a top-secret document and capture an unstoppable killer. And they have to pull it off without Uncle Sam, Larry's nosy father, catching on!