Danger on the Great Lakes

THERE'S MORE EXCITEMENT ON THIS CRUISE SHIP THAN NANCY BARGAINED FOR! Nancy, Bess, and George are going on a cruise around the Great Lakes for a fantastic end-of-summer vacation! As soon as the girls set foot on the ship, though, they smell something fishy. Their new friend Amber is upset because her boyfriend, Craig, is neglecting her. After a little investigating on her friend's behalf, Nancy learns that Craig is really a detective. He's been busy hunting for a mastermind diamond thief who may