The narrator hatches a plan. He orders a military gas mask, digging tools, and six carboys of sulfuric acid to be delivered to the cellar door of the house. He digs into the earthen floor of the cellar, turning up fungous yellow ooze, and arranges the barrels of acid around the hole in the belief that he will happen upon some kind of monstrous creature. Eventually, he uncovers a soft, blue-white, translucent tube, bent in half and two feet in diameter at its widest point. He frantically climbs out of the neck-deep hole, and dumps in four barrels of acid, realizing that he had found the "elbow" of a gigantic monster. The narrator faints after emptying the fourth barrel. When he awakens, the narrator empties the two remaining barrels, to no effect, replaces the dirt, and finds that the strange fungus has turned to harmless ash. He mourns his uncle, but is relieved to be sure that the horrible creature is finally dead. The narrator records that the house has subsequently been rented to another family, and that the house now appears completely normal.