eyond dispute and that was Mr. Shei’s complicity in the affair. The elusive and highly accomplished rogue already had a score of astounding crimes to his record, and the Thelma murder was hedged with all the mystery and baffling detail with which he loved to mask his exploits. Miss Darrow’s dying words were scarcely needed to turn the finger of suspicion in Mr. Shei’s direction. The absence of clews, the uncertainty in regard to the motive, the audacity that marked the crime itself as well as the subsequent snatching away of the body, all indicated a boldness and a finesse that left little doubt of Mr. Shei’s guilt. Even if his own hand had not executed the crime, it seemed practically certain that his mind had planned and conceived it.

But who was Mr. Shei? The whole train of surmises and theories pivoted on that question. Not much was known of him save that he had a passion for tantalizing the public and keeping the nerves of the men at headquarters on edge, and that his achievements had not been equaled in scope or brilliance of execution since The Gray Phantom’s retirement. He took a diabolical delight in flaunting his name before the world while keeping his person carefully out of the reach of the law’s long arm, and even the name was a challenge to the police and a teaser for the public imagination. Someone versed in dead languages had discovered that the word “shei” was the ancient equivalent of the modern x, the symbol of the unknown quantity, and it was generally agreed that the name fitted the elusive individual who bore it.

Yet the name meant nothing. It was only an abstraction, for it afforded no clew to its owner’s identity. The night before, while she sat beside her father in the Thelma Theater, a vagrant flash of intuition had come to Helen. She had seen the solution of the mystery in a swift, dazzling glimpse. The revelation had stunned and nearly blinded her, and thoug