He has been demanding a modest ten thousand pounds from Lady Constance Dex—Lady Constance being a sister of the Hon. and Rev. Harry Dex, Vicar of Great Bradley. The usual threat—exposure of an old love affair.

    "Dex is a large, bland aristocrat under the thumb of his sister; the lady, a masterful woman, still beautiful; the indiscretion partly atoned by the death of the man. He died in Africa. Those are the circumstances that count. The brother knows, but our friend Montague will have it that the world should know. He threatens to murder, if necessary, should she betray his demands to the police. This is not the first time he has uttered this threat. Farrington, the millionaire, was the last man, and curiously, a friend of Lady Dex."

    "It's weird—the whole business," mused Ela. "The two men you found in the square didn't help you?"

    T. B., pacing the apartment with his hand in his pocket, shook his head.

    "Ferreira de Coasta was one, and Henri Sans the other. Both men undoubtedly in the employ of Montague, at some time or other. The former was a well-educated man, who may have acted as intermediary. He was an architect who recently got into trouble in Paris over money matters. Sans was a courier agent, a more or less trusted messenger. There was nothing on either body to lead me to Montague Fallock, save this."

    He pulled open the drawer of his desk and produced a small silver locket. It was engraved in the ornate style of cheap jewellery and bore a half-obliterated monogram.

    He pried open the leaf of the locket with his thumbnail. There was nothing in its interior save a small white disc.

    "A little gummed label," explained T. B., "but the inscription is interesting."

    Ela held the locket to the light, and read:

    

    "Mor: Cot.

    God sav the Keng."

    

    "Immensely patriotic, but unintelligible and illiterate," said T. B., slipping the medallion into his pocket, and locking away the dossier in one of the drawers of his desk.

    Ela yawned.

    "I'm sorry—I'm rather sleepy. By the way, isn't Great Bradley, about which you were speaking, the home of a romance?"

    T. B. nodded with a twinkle in his eye.

    "It is the town which shelters the Secret House," he said, as he rose, "but the eccentricities of lovesick Americans, who build houses equally eccentric, are not matters for police investigation. You can share my car on a fog-breaking expedition as far as Chelsea," he added, as he slipped into his overcoat and pulled on his gloves; "we may have the luck to run over Montague."

    "You are in the mood for miracles," said Ela, as they were descending the stairs.

    "I am in the mood for bed," replied T. B. truthfully. Outside the fog was so thick that the two men hesitated. T. B.'s chauffeur was a wise and patient constable, but felt in his wisdom that patience would be wasted on an attempt to reach Chelsea.

    "It's thick all along the road, sir," he said.