Treachery at Martinique Isle

At the SW sea, turn your back to the inn
lies the key, Across the way.
Stay and it will lead ye, True to the marker
to set the treasure free, At last to dig in sand.
In the mid 1600's, when King Charles I reigned England and pirates controlled the seas, twins separated at birth are reunited under dire circumstances in the sleepy town of Port de Couler de Bateaux, Port of Sinking Ships. Jacqueline and Alexandria settle into the Midway Zebra inn with their new surrogate parents, innkeepers Jemima and Fred Bumbleridge. Eight years later, the inn burns to the ground, taking the beloved Bumbleridges with it. The twins are abandoned once more, but their guardians have left something to remember them by. Two small bags of gold, two cloaks, two flintlocks, and two gold lockets.
A riddle is inscribed on each locket, finishing not only a tale of piracy but also opening a door to the girls' mysterious past. Partnered with a thief, a butler, and a wannabe Viking, the two sail across the ocean in search of answers. Together the twins discover that not everyone is who they seem, and sometimes things take a turn for the worse especially when there is Treachery at Martinique Isle.