1951 - Dame Elspeth 'Holly' Hollanby and her no-nonsense dresser, Ivy, drive to west Wales to join a star-studded Christmas concert, a favour for a friend. At only their first rehearsal, they hear a young singer has died, one of a group of talented students nicknamed the Four Canaries. It is soon found to be poison and hers will not be the last murder... Holly and Ivy are equally at home with the stars at the ghostly Nanteos Mansion and the students in their seafront digs. Despite warnings from the dashing Inspector Lloyd, they know how to read between the lines with performers and can't help asking questions. They soon find themselves in a life-or-death race for the truth.