It took him but a second to reach the landing, and swiftly, silently he grasped the handle of the surgery door. It yielded to his touch, sprang open upon well-oiled hinges, and in another moment Cleek had achieved his object and stood in the little room. His eyes, trained to observe quickly, took in the shelves of drugs, once dispensed and used so freely by the dead doctor. The vast array of bottles stood dust covered and dull, many with spider's webs over the stoppers. All but one, that is, and at that one Cleek's heart gave a leap, and his hand shot out, then stopped poised over it. The label on the bottle bore the medicinal name for prussic acid, and the dust had been brushed from the neck and stopper. Around the centre lay the marks of long, slender fingers! Cleek's hand dropped again, and for a second he stood stock still, his brows knitted, the little nerve in his temple throbbing incessantly and his chin pinched up between one finger and thumb. Suddenly he switched on his heel, a new train of thought aroused by the sight of some white powdery atoms that lay at his feet. Cautiously he bent down and touched one of the crumbling balls. "Magnesia," he muttered. "By all the Gods--and that remnant of pellet in the dead man's mouth!" And the good Dr. Verrall was a friend of the family, so of course he would have access to this long-forgotten surgery which Cleek himself would never have known existed had it not been for the providential opening of the door. What, indeed, was the connection between Miss Jennifer and the dead "Miss Cheyne"?--or was it Dr. Verrall, after all? Bobby Wynne? Cleek dismissed him from his mind altogether as utterly harmless, though again there was the reluctance of that youth to allow him to enter this very room. There was the trail of magnesia, too. Now if he could find any trace of that most child-like and bland of medicines in Master Bobby's own room---- This thought caused a sudden recollection of the two below and he moved away quickly. Swiftly and as noiselessly as he had entered, he passed out, the problem rendered still deeper by the knowledge he had obtained. Darting into young Wynne's room, he gave it a lightning scrutiny, but there was no trace of magnesia to be found. But of course this room would be swept out every day and so no remnants of dust and powder would be permitted to lie there. Down the staircase he went once more, stopping only to withdraw his silver cigarette-case from the pocket it had never left, and his hand on the dining room door to open it, he stood rigid, for through it came Miss Jennifer's metallic and artificial voice. "Edgar, dear, you are sure we are safe? I don't trust this man----" "Perfectly safe, darling," came the deep-toned answer. "Leave everything to me and fear nothing. You shall be safe, that I swear."