The Book of the Beast by Tanith Lee

meekly, still her eyes lowered, afraid he would glimpse the fires in them.
    “The cup of parting,” said Helise. She employed the phrases of courtly songs, these came with facility, now she needed them, or Satan sent them, for how could she have a vocabulary to manage this?
    He accepted the wine slowly. He did not drink, but stood regarding her.
    Then, at last, at last, he raised the cup.
    She looked, and saw him swallow, once, twice.
    “What wine is this?” he said absently. His eyes were fixed on her. At their intensity a wonderful terror submerged her. Never, in any of their dealings, had he studied her in this way. It was the gaze of desire, or so it seemed. He drank again, not taking his eyes from her. And then he frowned, and said, “There’s something in the wine—did you mean to poison me?”
    “Oh no!” she cried. Her heart seemed cloven by its hammering.
    “But—what is it? What have you done to me?”
    “A love potion,” she said. The admission was safe now.
    “Then, there’s no choice.”
    He smiled, grinned with the deadly dead mirth she had witnessed once before, and tilting the glass he drained it, and let it go. It crashed in bits upon the floor.
    “Perhaps, Helise,” he said, “perhaps you haven’t been sensible. Come here.” And when she took a step, he took several more to meet her, and caught her between his hands. “Love potions,” he said. “Did you think I didn’t want you? For every night spent in bed with you, first a draught to make me sleep. So that I shouldn’t be tempted. For you’re adorable, my white wife. Better than any dream. But perhaps the dreams won’t matter now—’
    The earth gave way and the room broke off in shards. She clung to him and he kissed her, a kiss of serpents, his tongue in her mouth.
    His hands were those of a saviour, supporting, rescuing her in tumult, but also the hands of one who would destroy her, finding purchase on her body, ripping at the laces of her gown—
    She had unleashed desire, the carnal entity. His breath burned on her throat. He held her so tightly she herself could not breathe. He bore her backwards and the hard floor was harsh under her uncushioned slimness. His weight pushed her down. A sore sweetness shot through the core of her breasts as he drew on them with his lips. Almost delicious but partly horrible—almost a torment—and then a tickling and probing between her thighs so her instinct was to evade—but he would not allow her now to evade him, and then came a terrible pressure, like that of a thunderbolt trying to cleave her, and she felt she would be burst, but there was only a shrill tearing, like a broken string.
    She saw his face as he invaded her. She did not know him. He bore upon her, his skin engorged with lust and his eyes opaque and perhaps unseeing. There seemed no longer any contours to his face. He did not behold her and was unrecognisable. His hair tossed about him, shaggy as the mane of a beast, lank and dark with sweat as if with blood—
    The thrusting of his body within hers was a punishment, a horror that was nearly an ecstasy, and far worse for that.
    Helise heard herself moaning and pleading in pain. The fire-making action of his loins scorched her. She struggled, and the ghostly ecstasy surged in her again, and she no longer cared what had mounted on her, what killed her there on the ungiving ground. It was not Heros. It was some hideous thing, some creature of the Devil, torturing her in Hell for all her sins—
    She heard terrible sounds rising in her throat, and then the spasm hurled her apart. She was screaming. It would never end. In animal fear she let go her clutch upon the excruciating peak, and fell away.
    Only then was she revolted, finding herself on the floor, ground into the tiles under the weight of him, a hard mass of flesh that still moved upon her, still thrust mercilessly inside her.
    He was lifting himself up, his head thrown back—
    On the arch of his throat, the weltered