The appearance of the roof above had puzzled him for an instant as the light touched it, then in the next had filled his very soul with loathing and horror. For directly above them was moving a black patch, a foot or so in extent ... and it was composed of a dense moving mass of tarantula spiders! A line of the disgusting creatures was mounting the wall and crossing the ceiling, ever swelling the unclean group! Dr. Cairn did not hesitate to leap for the stair, and as he did so the spiders began to drop. Indeed, they seemed to leap towards the intruders, until the floor all about them and the bottom steps of the stair presented a mass of black, moving insects. A perfect panic fear seized upon them. At every step spiders _crunched_ beneath their feet. They seem to come from nowhere, to be conjured up out of the darkness, until the whole cellar, the stairs, the very fetid air about them, became black and nauseous with spiders. Half-way to the top Dr. Cairn turned, snatched out a revolver and began firing down into the cellar in the direction of the sarcophagus. A hairy, clutching thing ran up his arm, and his son, uttering a groan of horror, struck at it and stained the tweed with its poisonous blood. They staggered to the head of the steps, and there Dr. Cairn turned and hurled the candle at a monstrous spider that suddenly sprang into view. The candle, still attached to its wooden socket, went bounding down steps that now were literally carpeted with insects. Tarantulas began to run out from the trap, as if pursuing the intruders, and a faint light showed from below. Then came a crackling sound, and a wisp of smoke floated up. Dr. Cairn threw open the outer door, and the two panic-stricken men leapt out into the street and away from the spider army. White to the lips they stood leaning against the wall. "Was it really--Ferrara?" whispered Robert. "I hope so!" was the answer. Dr. Cairn pointed to the closed door. A fan of smoke was creeping from beneath it. * * * * * The fire which ensued destroyed, not only the house in which it had broken out, but the two adjoining; and the neighbouring mosque was saved only with the utmost difficulty. When, in the dawn of the new day, Dr. Cairn looked down into the smoking pit which once had been the home of the spiders, he shook his head and turned to his son. "If our eyes did not deceive us, Rob," he said, "a just retribution at last has claimed him!" Pressing a way through the surrounding crowd of natives, they returned to the hotel. The hall porter stopped them as they entered. "Excuse me, sir," he said, "but which is Mr. Robert Cairn?" Robert Cairn stepped forward. "A young gentleman left this for you, sir, half an hour ago," said the man--"a very pale gentleman, with black eyes. He said you'd dropped it."