The Master of Darkness proves that "crime does not pay" in two thrilling pulp novels by Walter B. Gibson. First, The Shadow knows that "The Four Signets" hold a secret message that spreads crime and murder in their deadly wake! Then, the bequest of a rosewood music box leads to "Five Keys of Crime" that can provide its young heir with a fabulous inheritance-if he lives long enough to collect it! Plus, a Hollywood star steals the picture when female sleuth Carrie Cashin investigates the mystery of "The Three X's" in a tale by Theodore Tinsley.