King Triton and his daughters have traveled to the icy waters of the Artic Ocean to visit an old family friend. Soon after they arrive, the princesses learn that the palace where they're staying is rumored to be haunted by the ghost of a merman named Morven, who died a horrible death there many years earlier. At first Ariel and her sisters are skeptical, but when strange and spooky things begin to happen, they have to admit that it really does seem as if someone - or something - is after them. Could it really be the ghost of Morven?