The Problem of the Green Capsule by John Dickson Carr

behind him. It was colder here, in the narrow aisle of grass between the house and the spectral yellow chestnut trees. It was also darker, now that some lights were dimmed and only an ordinary bulb burned in the office. He felt the effect of that dead hour of the night when flesh and bone seem brittle. He also thought he heard a bell ringing faintly somewhere. But he paid no attention to it, for his attention was concentrated on Dr. Nemo’s properties lying outside the office windows.
    That black satchel——
    Now he knew why its appearance had seemed vaguely familiar. Larger than a doctor’s medicine-case, though of much the same shape, and yet not large enough for an ordinary valise. Such a bag was one of the exhibits on display in the Black Museum at Scotland Yard.
    He knelt down by the bag, which stood near the hat and the raincoat. It was of varnished leather, and looked new. Dr. Nemo’s name had been painted on the side, rather crudely, with a stencil. Using his handkerchief, Elliot opened the bag. Inside was a two-pound box of Henrys’ Chocolate Caramels, designed with bright green flowers.
    “That’s got it,” he said aloud.
    This bag was the Shop-Thief’s Friend. He picked it up and looked at the bottom. Originally used for conjuring entertainment, its principle had been adopted by the gentry who raid department-stores, jewelers, any shop in which valuable goods are exposed openly.
    You enter a shop, carrying this innocent-looking bag. You put it down casually on the counter, while you looked at something else. But you put the bag down over what you wanted to steal. The bottom was equipped with the conjuror’s “spring-grip” device, which snapped up into the bag what lay underneath. You then—having made no suspicious move of any sort—picked up your bag and left the shop.
    Dr. Nemo’s genial course became clear. He had entered the office, put his bag on the table, and, when doing so, had turned his back to the audience. He had put down the spring-grip bag not in front of the green box, but on top of it. The bag would deal with much heavier objects than a comparatively small and light chocolate-box. In the deep pocket of his raincoat he had a blue box of chocolate peppermints. Either while bending over to put down the bag, or when bending over to pick it up again, he had slipped the other box behind the satchel under cover of turning his back. Before an already be-dazzled and flurried audience, it would require no great skill. And all this had been done with Marcus Chesney’s aid, at Marcus Chesney’s direction, as a part of Marcus Chesney’s scheme to trick the witnesses wherever they turned their eyes…
    But how did this fact help towards a solution of this crime, or of the crime at the sweet-shop? Did it mean that at Mrs. Terry’s one whole box of chocolates had been substituted for another?
    “Hoy!” whispered a voice.
    Elliot jumped. It was a hoarse voice, whispering firecely, and it came from directly above his head. He peered up, to see Dr. Joseph Chesney’s face looking down at him from a window on the floor above. Doctor Joe was leaning so far out of the window that Elliot wondered whether that great weight would come tumbling down like a laundry-bag.
    “Are you all deaf down there?” whispered Doctor Joe. “Don’t you hear the doorbell ringing? Why don’t somebody answer it? It’s been ringing for five minutes. Curse it all, I can’t do everything. I’ve got a patient here——”
    Elliot woke up. That, of course, would be the police-surgeon, the photographer and fingerprint-man, who had to be summoned from twelve miles away.
    “And—hoy!” roared Doctor Joe.
    “Yes?”
    “Send Marjorie up here, will you? He’s calling for her.”
    Elliot looked up quickly. “Is he conscious? Could I see him?”
    A rusty, hairy fist, its loose sleeve dangling, was shaken at him from the window. Illuminated from below, Doctor Joe’s gingery beard had an aspect almost