Emily and Sophie age 9, and Jack age 8, are at Blackthorn Stables, getting ready for the St. Patrick's Day parade. As they are riding their ponies back to the stables they stumble upon an ancient silver brooch, rumoured to be from the legendary Silver Serpent Schooner. This Spanish ship, laden with gold and treasure, is said to have met its watery grave centuries ago in the mysterious depths of Blackthorn Bay, Galway, Ireland. But disaster...