Scooby's nerves are frazzled so the gang goes on a cruise. Unfortunately, their travel agent is one of the thirteen ghouls, and he sends the gang on a trip into the Bermuda Triangle.

At the Mardi Gras, Vincent is smitten by the lethal love trance of Nekera, a beautiful femme fatale. The gang thinks they must keep him from her kiss; however, Vincent knows that kiss will be Nekera's undoing.

Three hags are given magical powers by a witch trapped in another dimension. When the gang learns of their plot to overthrow the world, Vincent sets out to thwart the mist witch.