The detective proved that he could, provided that he were helped, but he found it difficult. “When the manager, and that American gentleman, left No. 14 last night, did you see them go on down the stairs?” “I saw them turn on to this landing, sir, but I couldn't see this window from where I was. I thought I heard their footsteps go on down.” “The wind was rather rough. One or both might have come up quietly again and got out.” “I don't think anyone could have opened that window without my hearing them. And I think I should have felt the draught, sir.” “Humph!” was all Pointer said to himself, as he walked on out of the hotel and took a train to Streatham, where lived Doctor Burden, the great Government analyst, expert in poisons, and reasons for sudden deaths. Pointer had barely pushed open the gate of the drive when the doctor met him, swinging along, golf sticks under his arm. Too late he tried to dodge behind a clump of laurels, the law was upon him. “Just a moment, doctor. It's only for a second, sir,” begged the police officer, with a firm grip on the clubs. “It really won't take you more than one glance. All I want to know is whether a spot on a label is morphia solution or not. That's all.” “I know you, Pointer.” The doctor tried to wrest his irons free; “you got me last time with that yarn, and tied me up in a thirty-six hour job before I knew where I was. Never again!” “But this time it really is only one spot of what I think may be a solution of morphia that I'm after.” He won, and the doctor, growling at his folly in having gone to Service instead of straight on to the links, led him into his study. Pointer unpacked the bottle of cough-mixture which he had taken from the washstand in No. 14. “Here, sir, where the writing has run a bit on the label. Could that smear be morphia? The stuff in the bottle is all right, I fancy, but it'll be sent to you to-morrow to test at your leisure.” “Leisure!” groaned the analyst, “you're a wag. My leisure!” He took the bottle and disappeared through a door to return in a couple of minutes. “It _is_ morphia. And in a solution strong enough to kill an elephant. Don't ask me for exact quantities, I'm off.” “Very much obliged to you, sir,” grinned the Chief Inspector, as he carefully replaced the bottle, and followed the doctor at a more leisurely pace out of the garden. “The case begins to move at last,” he murmured to himself with satisfaction. He proceeded to jog along still further by ringing the private bell of Mr. Redman, the chemist, until that gentleman opened the door. At the sight of the officer, whom he knew, his face softened a little from its “disturbed-at-Sunday-dinner” severity. “Anything I can do for you, officer?” He waved him into the passage. “It's just this, Mr. Redman,” this time the print of young Eames was produced. “Do you remember selling anything to this gentleman any day last week, or say since about July 25th?” The chemist shook his head.