Grandpa Dachshund tells his seven grand puppies the story of how Tiller, a dachshund who loves to sail, and Turnbuckle, the calico cat who loves adventure, set out on a quest to find buried treasure. In the Bahama Islands, the two are given a gold skeleton key. While sailing to the Chesapeake Bay, Tiller polishes the key and discovers the word 'Borthwick' etched in its side. Sure that this is a clue to the location of the buried treasure, the two set out on an ocean voyage to the British Isles to uncover the mystery of the gold skeleton key and find the treasure so it can be returned to its rightful owner. But can they survive the Bermuda Triangle or a fierce storm at sea? Join Tiller and Turnbuckle in a race against time as they battle pirates, rats, badgers, a sea serpent and more.