Then he noticed a block of red marble in the shadow of a tree. He rode up to it and dismounted, very puzzled, and sat down on the stone and invoked God and Saint Peter; and thereupon he heard a creature inside the stone cry:

‘Oh, good sir! Free me from my pain and torment! I tell you, my dear, kind friend, I’m suffering dreadful torture, but you can rescue me!’

Perceval jumped up when he heard the voice, and leaned over the stone and said: ‘I can’t release you – this block’s too huge! It baffles me how you ever got in! You’ll never get out, I promise you, unless you tell me how to set you free. If I do, I bid you by all the power of God, tell me truly who you are and what you’re up to.’

‘Oh, I will!’ the creature said. ‘But free me from this torture! Step forward and stand firm, and pull out the spike that’s skewering my body and stops me moving: then you’ll see what’ll happen!’

So Perceval went up to the stone and found an iron spike, stiletto-sharp – that’s no exaggeration: it was sharper even than that. He went ahead and drew it from the stone; and then, very slowly, from the little hole he saw a worm emerge, and these verses assure us it was fully six feet long. Suddenly it shot off faster than a crossbow bolt. Perceval was dumbstruck – he’d no idea what had become of it. But the air, he saw, was so full of fire he was sure the worm must be burning alive, and he heard thunder and a roaring wind: it seemed the sky was about to crumble into an abyss! He was afraid – and not a little! He realised a demon had deceived him – he was distraught and filled with dread. But the terrible storm didn’t last long enough to boil an egg; and when Perceval saw the weather clear he sat down on the marble block beneath the tree and pondered on the worm.

Then he saw a beast approaching. It had the head of a man but the body of a snake. And at once it said to Perceval:

‘I’ve come to do as I said. Ask whatever you wish – you bade me answer by the power of the One who created and made me. But we were undone by Lucifer’s pride at our having been made so beautiful: his self-regard cost us dear! It angered God the Father, and He cast us down in torment from His holy, glorious heavens where the proud will never enter. Since you freed me from that stone I’ve destroyed a city and laid waste the land: within a day’s ride on every side there’s not a town or tower or castle where I’ve left a building standing – I’ve ruined and destroyed them all! You’ll see for yourself if you ride on: if you carry on along this path you’ll die crazed with hunger!’

‘You’re lying!’ said Perceval. ‘I swear by God you are! The creature that uttered those mighty cries and slithered from the hole was a tiny, slender thing! Your serpent’s body is huge! And you’ve the head of a man, it seems. When I look at your face you seem gentle-natured – though your body’s hideous, foul! So I don’t believe you – you’re not the one I freed from the stone!’

‘Listen to me,’ the demon said. ‘I tell you this: in such a shape as I am now the Devil tricked Eve! He’d have striven in vain if she’d seen his body – he’d never have deceived her then! He hid his body so that Eve didn’t spot it! That’s why I’ve assumed this shape – I’ve tricked people far more easily like this! I’ll do much more evil now I’m freed from the stone; Merlin put me there by magic, so I wouldn’t be able to use my wiles to thwart the one who’s seeking the grail – he’ll never be able to find it now I’m out of the stone! He’ll be wasting his time – he’ll never achieve his goal!’

‘By my life,’ said Perceval, ‘now I know you’re lying! I’ll not believe a word of it – unless I see you go back in the stone in the form of the thing I released just now! If you’re that creature, turn into it again and return to the hole: then I’ll believe you – and pick your brains on another matter. But you can’t – you’re no shape-changer!’

‘Right! You’ll see!’ the demon cried, and turned into a worm and was back in the stone before you could count to four! Perceval dashed up and rammed the spike back in the narrow hole; the demon was so distraught that he screamed and howled, yelling: ‘Mercy, kind sir! Let me out of here! I’ll never do anyone harm or shame or wickedness again!’

Gerbert's Continuation of Perceval