But the horse was bent on tricking him, intent on evil, and the moment it felt his weight upon its back it stormed away whinnying, destroying everything in its path, wrecking trees, smashing branches, till it reached a cliff above a great, deep river, wider than the range of a catapult, and was about to hurl itself in and bear Perceval to his death. Perceval gaped down at the river, never guessing he was on a demon’s back; but at the prompting of God he raised his hand and crossed
himself, and the moment he made the sign of the cross the demon, who abhorred that sign, desperate though it was to drown him, reared and flung Perceval from its back to the ground as it launched itself from the cliff and into the river. If a tower had been demolished and crashed in a heap it wouldn’t have made such a thunderous din as the horse as it hit the water!

Third Continuation of Perceval