them with heavy rain that stung their faces and soaked them to the skin.
‘That's the Edgeland wind,’ called back the librarian on the library sledge. ‘We must be getting close!’ He cracked the whip and urged the yelping prowlgrins on.
The rope round Rook's middle jerked taut, forcing him to quicken his pace. All round him, the air was filled with curses and moans as the marchers struggled to keep up.
Suddenly, rising above it all, there came the noise of squelching mud, and a curious plaff-plaff sound. Rook looked up. To the left of the column, a cluster of low mud-dunes seemed to be approaching, rising and falling in a slippery rhythm as they did so.
‘MUGLUMPS!’
The cry went up from the back of the column, where the Ghosts of Screetown had obviously spotted the danger.
The rope suddenly tugged Rook violently to the right as the librarian on the library sledge battled to control the panicking prowlgrins. Ahead, the four other sledges were in equal trouble. The low shapes were gathering and, from their path, it was obvious that the closely harnessed packs of prowlgrins were their intended prey.
Felix and his ghosts appeared out of the gloom on all sides. Fenbrus Lodd, Cowlquape beside him, shouted desperately to his son.
‘The library sledges! Felix!’ he screamed. ‘They're after the sledges!’
Rook was running now, with Xanth and the bander-bears dragged behind him, as the library sledge careered across the mud.
‘Cut yourselves loose!’ shouted Felix to Rook and the other librarians. ‘And follow the braziers of the sky pirates!’
With a grunt, Rook tore at the knotted rope round his middle and slid to a halt as it fell free.
‘There!’ shouted Xanth, beside him. He pointed.
Ahead, Deadbolt stood on a mud-dune, waving a flaming purple brazier over his head as if possessed. ‘Rally to me, Undertowners!’ he roared. ‘Rally!’
The huge library sledges slewed and skidded away to the right, the yelping screams of the prowlgrin teams drowning out the cries of their drivers. The mud-dunes seethed and boiled with the low, flapping shapes of the half-hidden muglumps in pursuit.
Panting, Rook reached Deadbolt, who was now surrounded by a huge crowd of mud-spattered and bewildered Undertowners. Xanth and the banderbears came lumbering up behind him.
‘There lie the Edgelands, Sky help us! We'll regroup there!’ shouted Deadbolt above the howling winds, and pointing to a low, grey ridge in the middle distance. ‘Mothers and young'uns first!’
The Undertowners surged forwards across the glistening wind-flattened expanse of mud ahead, all eyes fixed on the distant ridge. Every one of them was driven by a desperate, half-mad frenzy to get out of the clinging mire mud and onto dry land. Rook was jostled and bumped as Undertowner after Undertowner barged past.
‘You heard him!’ Xanth shouted. ‘Come on. We're nearly there, Rook!’
But Rook shook his head. ‘I'm a librarian knight,’ he said in a low voice, his words almost lost in the gusting wind. ‘My place is with the library.’
He turned back towards the library sledges. Xanth and the banderbears hesitated. It was obvious from their eyes that they shared the Undertowners' mire-madness. Every fibre of their beings longed to be rid of the terrible white mud.
‘And our place is with you,’ said Xanth.
They turned and fought their way through the crowd, and back out into the Mire. The library sledges, like huge lumbering beasts, were away to the right, and had halted their mad dash. Now they seemed marooned, their tops bristling with librarians like hairs on a hammelhorn. Asthey approached, Rook could see why.
Felix and the ghosts were busy cutting the traces that harnessed the prowlgrin teams, while his father waved his hands in the air wildly, from on top of one of the sledges.
‘Stop! Stop!’ he was bellowing, but Felix ignored him as he cut through another tilderleather strap.
The slithering mounds had congregated in a