Retired soldier Alex Easton, formerly of the Gallacian army, receives word that kan childhood friend Madeline Usher is dying. Ka journeys to the Ushers' ancestral home in
Ruravia and finds it in disrepair, surrounded by fungus and a dark, unsettling
tarn. Roderick Usher, Madeline's twin brother and Easton's subordinate, has become nervous and frail in the intervening years. Madeline is terminally ill, suffering from
catalepsy. She appears
cachectic, and Easton is disturbed by the thin, wispy appearance of the hair on her arms. Also present are Eugenia Potter, a mycologist; James Denton, an American doctor; and Angus, Easton's
batman. Easton tries to convince Madeline to leave the moldering mansion for her own health, but she refuses. Easton notices that the
hares near the tarn behave oddly, as if they are infected with an unknown disease. Ka sees strange lights moving in the tarn at night. Madeline begins sleepwalking, and her stilted gait reminds Easton of the hares. Easton postulates that Madeline and the hares have the same illness. Ka shoots a hare and attempts to dissect it, but the dead hare begins to crawl away. Easton, terrified, flees back to the manor. Madeline dies; her body is placed in the crypt. Roderick claims to hear her knocking on the doors of the crypt, trying to get out. Easton visits Madeline's body and finds that her neck is broken. Eugenia deduces that the changes in Madeline's hair were due to fungal
hyphae. Easton brings her to examine the body, but it has vanished in the interim. While Roderick sleeps, the others dissect a hare and find it full of fungus. The carcass continues to move on its own, seemingly controlled by the infestation. Denton admits that Roderick killed Madeline, believing her to be possessed. They enter Roderick's bedroom, where they find Madeline sitting on the bed, her neck hanging at a shocking angle. Madeline tells them that she has been dead for at least a month; the fungus from the tarn is reanimating her body. Madeline tells them that the tarn is conscious and sentient, and that it is learning how to communicate with them. She asks Easton to let it infect kan, giving it a home after her corpse breaks down. Easton and Denton flee; Roderick stays behind to burn down the house, with himself and Madeline's corpse still inside. The survivors poison the tarn with sulfur, killing the remaining fungus. ==Reception==