"It's supposed to be a poison case, although I can't see it myself," answered the detective--to whom Keppel Stuart's unusual knowledge of poisons had been of service in the past; "but if what I suspect is true, it's a very big case all the same." Laying down his pipe, which he had filled but not lighted, Inspector Dunbar pulled out from the inside pocket of his tweed coat a bulging note-book and extracted therefrom some small object wrapped up in tissue paper. Unwrapping this object, he laid it upon the table. "Tell me what that is, doctor," he said, "and I shall be obliged." Stuart peered closely at that which lay before him. It was a piece of curiously shaped gold, cunningly engraved in a most unusual way. Rather less than an inch in length, it formed a crescent made up of six oval segments joined one to another, the sixth terminating in a curled point. The first and largest segment ended jaggedly where it had evidently been snapped off from the rest of the ornament--if the thing had formed part of an ornament. Stuart looked up, frowning in a puzzled way. "It is a most curious fragment of jewellery--possibly of Indian origin," he said. Inspector Dunbar lighted his pipe and tossed the match-end into the fire. "But what does it represent?" he asked. "Oh, as to that--I said a _curious_ fragment advisedly, because I cannot imagine any woman wearing such a beastly thing. It is the _tail of a scorpion._" "Ah!" cried Dunbar, the tawny eyes glittering with excitement. "The tail of a scorpion! I thought so! And Sowerby would have it that it represented the stem of a Cactus or Prickly Pear!" "Not so bad a guess," replied Stuart. "There _are_ resemblances--not in the originals but in such a miniature reproduction as this. He was wrong, however. May I ask where you obtained the fragment?" "I'm here to tell you, doctor, for now that I know it's a scorpion's tail I know that I'm out of my depth as well. You've travelled in the East and lived in the East--two very different things. Now, while you were out there, in India, China, Burma, and so on, did you ever come across a religion or a cult that worshipped scorpions?" Stuart frowned thoughtfully, rubbing his chin with the mouthpiece of his pipe. Dunbar watched him expectantly. "Help yourself to whiskey-and-soda, Inspector," said Stuart absently. "You'll find everything on the side-table yonder. I'm thinking." Inspector Dunbar nodded, stood up and crossed the room, where he busied himself with syphon and decanter. Presently he returned, carrying two full glasses, one of which he set before Stuart. "What's the answer, doctor?" he asked.