Nancy Drew travels to Castle Malloy in Ireland to be the maid-of-honor in her friend Kyler Mallory's wedding. As Nancy drives towards the castle, a ghostly figure darts out in front of her car. The car crashes into a ditch, and Nancy is stuck at the site of a new mystery. Kyler's wedding was supposed to be the biggest event in Bailor since half the castle blew up sixty years ago, but now the groom is missing. Was he snatched by the banshee rumored to haunt the castle, or is this a case of cold feet? It's up to Nancy to find the groom and save this wedding.​