This was the third week of Selwood's secretaryship to Jacob Herapath. Herapath was a well-known man in London. He was a Member of Parliament, the owner of a sort of model estate of up-to-date flats, and something of a crank about such matters as ventilation, sanitation, and lighting. He himself, a bachelor, lived in one of the best houses in Portman Square; when he engaged Selwood as his secretary he made him take a convenient set of rooms in Upper Seymour Street, close by. He also caused a telephone communication to be set up between his own house and Selwood's bedroom, so that he could summon his secretary at any hour of the night. Herapath occasionally had notions about things in the small hours, and he was one of those active, restless persons who, if they get a new idea, like to figure on it at once. All the same, during those three weeks he had not once troubled his secretary in this fashion. No call came to Selwood over that telephone until half-past seven one November morning, just as he was thinking of getting out of bed. And the voice which then greeted him was not Herapath's. It was a rather anxious, troubled voice, and it belonged to one Kitteridge, a middle-aged man, who was Herapath's butler.In the act of summoning Selwood, Kitteridge was evidently interrupted by some person at his elbow; all that Selwood made out was that Kitteridge wanted him to go round at once. He dressed hurriedly, and ran off to Herapath's house; there in the hall, near the door of a room which Herapath used as a study and business room, he found Kitteridge talking to Mountain, Herapath's coachman, who, judging by the state of his attire, had also been called hurriedly from his bed."What is it, Kitteridge?" demanded Selwood. "Mr. Herapath ill?"The butler shook his head and jerked his thumb towards the open door of the study."The fact is, we don't know where Mr. Herapath is, sir," he answered. "He hasn't slept in his bed, and he isn't in the house.""Possibly he didn't come home last night," suggested Selwood. "He may have slept at his club, or at an hotel."The butler and the coachman looked at each other-then the coachman, a little, sharp-eyed man who was meditatively chewing a bit of straw, opened his tightly-compressed lips."He did come home, sir," he said. "I drove him home-as usual. I saw him let himself into the house. One o'clock sharp, that was. Oh, yes, he came home!""He came home," repeated Kitteridge. "Look here, sir." He led the way into the study and pointed to a small table set by the side of Herapath's big business desk. "You see that tray, Mr. Selwood? That's always left out, there, on that table, for Mr. Herapath every night. A small decanter of whiskey, a syphon, a few sandwiches, a dry biscuit or two. Well, there you are, sir-he's had a drink out of that glass, he's had a mouthful or so of sandwiches. Oh, yes, he came home, but he's not at home now! Charlesworth-the valet, you know, sir-always goes into Mr. Herapath's room at a quarter past seven every morning; when he went in just now he found that Mr. Herapath wasn't there, and the bed hadn't been slept in. So-that's where things stand."Selwood looked round the room. The curtains had not yet been drawn aside, and the electric light cast a cold glare on the various well-known objects and fittings. He glanced at the evidences of the supper tray; then at the blotting-pad on Herapath's desk; there he might have left a note for his butler or his secretary. But there was no note to be seen.