From that frightful smell and that uncanny noise Willett's attention could no longer be diverted. Both were plainer and more hideous in the great pillared hall than anywhere else, and carried a vague impression of being far below, even in this dark nether world of subterrene mystery. Before trying any of the black archways for steps leading further down, the doctor cast his beam of light about the stone-flagged floor. It was very loosely paved, and at irregular intervals there would occur a slab curiously pierced by small holes in no definite arrangement, while at one point there lay a very long ladder carelessly flung down. To this ladder, singularly enough, appeared to cling a particularly large amount of the frightful odour which encompassed everything. As he walked slowly about it suddenly occurred to Willett that both the noise and the odour seemed strongest directly above the oddly pierced slabs, as if they might be crude trap-doors leading down still deeper to some region of horror. Kneeling by one, he worked at it with his hands, and found that with extreme difficulty he could budge it. At his touch the moaning beneath ascended to a louder key, and only with vast trepidation did he persevere in the lifting of the heavy stone. A stench unnameable now rose up from below, and the doctor's head reeled dizzily as he laid back the slab and turned his torch upon the exposed square yard of gaping blackness.