Inspector Head, having ascertained that Edward Carter has been shot down at his own door at four o'clock on a January morning, finds in the snow the murderer's footprints, leading to a gate, and stopping there! The tracks do not go on, nor do they reappear anywhere: the murderer, having walked as far as the gate, apparently vanished into thin air! This is the initial problem in a mystery into which is woven the love story of Hugh Denham and Marguerite West - but it is by no means the final or greatest problem of the book. Here is not only mystery, but a very human story. Charles Henry Cannell (1882-1947) was a prolific English author who wrote many mystery, adventure, western and fantasy novels under the pseudonyms E. Charles Vivian, Jack Mann and Barry Lynd.