Then he noticed a small door at the farther end of the room, and calmed himself enough to approach it and examine the crude sign chiselled above. It was only a symbol, but it filled him with vague spiritual dread; for a morbid, dreaming friend of his had once drawn it on paper and told him a few of the things it means in the dark abyss of sleep. It was the sign of Koth, that dreamers see fixed above the archway of a certain black tower standing alone in twilight—and Willett did not like what his friend Randolph Carter had said of its powers. But a moment later he forgot the sign as he recognised a new acrid odour in the stench-filled air. This was a chemical rather than animal smell, and came clearly from the room beyond the door. And it was, unmistakably, the same odour which had saturated Charles Ward's clothing on the day the doctors had taken him away. So it was here that the youth had been interrupted by the final summons? He was wiser than old Joseph Curwen, for he had not resisted. Willett, boldly determined to penetrate every wonder and nightmare this nether realm might contain, seized the small lamp and crossed the threshold. A wave of nameless fright rolled out to meet him, but he yielded to no whim and deferred to no intuition. There was nothing alive here to harm him, and he would not be stayed in his piercing of the eldritch cloud which engulfed his patient.