Phthor by Piers Anthony

“Nice,” he said appreciatively. “I seem to remember something like this, vaguely. I think the first time Chthon guided me through the caverns, using the half-woman...”
    “Black-haired?” Arlo asked.
    “Yes. Half-zombie. Don’t tell me she’s still around?”
    “Yes. She’s one of the Norns.”
    “Norns!” Aton exploded, laughing. “Chthon must have quite a sense of humor, deep in its stone circuits. She was a Lower Cavern bitch, when I knew her.”
    Bitch. The female of an Old Earth dog, evidently a term of disrespect. But now they were coming into Arlo’s particular garden near the falls, where the girl lay.
    Ex remained as she had been. Arlo had difficulty looking. It was not the sight of wounds and blood that bothered him, but the fact that he had so recently known this person, and in fact had some responsibility for her condition.
    “She’s been gutted, but she lives,” Aton said. “That’s remarkable. Are you sure she’s not zombie?”
    “She’s human! Chthon tried to take her—and then sent the wolf.”
    Aton looked up. “Wolf?” he asked sharply, evidently making the same connection Arlo had. A wolf had freed Bedside from the caterpillar...   “That’s what it felt like. Its mind. Bedside blocked me off, so I came too late and hardly saw it. Big—big, like a wolf.’’
    “You’ve never seen a wolf!”
    “I’ve seen the pictures in LOE. But it’s only the feel I mean. The malignancy. It doesn’t matter what it looks like. It’s a wolf.”
    “A wolf,” Aton repeated. “You’re right: in the caverns, feel is more important than appearance.” Then he shook himself. “So you’ve got a girl! She must have strayed from the prison.”
    “Yes. She said so.” But now Arlo was aware of a certain deviousness in his father and knew he was concealing something. Aton should have been surprised, perhaps angry—but he was neither. He could hardly be in collusion with Chthon. So what did he know?
    “We can’t save her,” Aton said regretfully. “Her guts have been spilled. I don’t know what keeps her alive.”
    There were times when his father lacked tact. Yet it was true. There was no explaining what kept Ex breathing. “We have to try,” Arlo said.
    “All we can do is tie her together and see what happens. Only Chthon can save her.”
    “But Chthon won’t.”
    The man’s eye looked at him, and Arlo knew the question was rhetorical. “Why not?”
    “Because Chthon sent the wolf to kill her!”
    Aton nodded. He gathered strong vines from the native flora of the garden. “Don’t you think Chthon could have arranged to kill her outright, instead of leaving her hanging by a thread?”
    “I—” But his arrival could not have had much effect; the wolf had already been departing. “Chthon wanted her—this way?”
    “It is possible to bargain with Chthon. That’s how I saved your mother.”
    Arlo was torn by hope and incredulity. “You—?”
    “She had the chill.”
    “The chill?”
    “I forgot. That’s not in LOE.” He sighed. “I hate this business. I think your girl is going to die, so I’m talking about something else. But maybe this will help.” He paused, finding his mental place as his hands worked, preparing the vines. “Most of what I know about the chill I learned from fat Hasty. That’s Hastings—a fellow prisoner, a quarter-century ago. Hasty, Framy, Bossman, Garnet, the black-haired bitch—I never did know her name—”
    “Verthandi.”
    Aton snorted, but continued: “Two hundred forty-one denizens of the nether caverns, and as many more in the upper prison. But Hasty was special. He knew everything, except how to mine a garnet. He died stuck in a hole, chopped in half by Bossman’s axe. Had to be done, because the jelly whale was coming...”He trailed off.
    “You mean a potwhale?” Arlo asked.
    “Hasty did a marvelous presentation. He phrased the mystery of the chill as though it were a parody of the earlier quest for the nature of