Courage and Muriel go on a much needed trip to get away from Eustace. They go aboard the Katz submarine and Muriel is put to work making tea. Courage is really not allowed on the ship but he sneaks into someone’s suitcase and pretends to be a ventriloquist dummy. He finds out that Katz plans to sink the ship with everybody on it. Courage burps up bubbles and everybody floats to the surface to safety,except Katz who gets ate by a shark.