When the Shuggazoom is attacked by aquatic monsters, the Hyperforce are saved by Captain Protesus. He tells the team that the monsters are only the beginning and an ancient demon entombed deep under the sea will awaken by the next dawn. Only the black crystal from the Hostile Depths can save them. But does the Captain want to stop the ancient monster or release it?Guest appearance: John Rhys-Davies as Captain Proteus