The Finishing Stroke

When a young Ellery Queen is invited to a house party over the holidays, the twelve days of Christmas turn out to be, quite literally, murder. As a series of anonymous gifts are sent with increasing menace, Ellery tries to unravel the mystery of who is sending them. What is their meaning? And what do they have to do with the identity of the murderer? Ellery Queen is flummoxed until decades later he comes across his diary and begins the investigation anew. Can he finally deduce who is the mystery killer?