The axe hovered in front of his nose again.
'I was just asking,' said Sock, in a desperate and distant voice.
'There's a man of the Watch in there freezing to death,' said Cuddy.
There was quite a crowd around them when they finally got the main door open. Lumps of ice clinked on the stones, and there was a rush of supercold air.
Frost covered the floor and the rows of hanging carcasses on their backwards journey through time. It also covered a Detritus-shaped lump squatting in the middle of the floor.
They carried it out into the sunlight.
'Should his eyes be flashing on and off like that?' said Dibbler.
'Can you hear me?' shouted Cuddy. 'Detritus?'
Detritus blinked. Ice slid off him in the day's heat.
He could feel the cracking up of the marvellous universe of numbers. The rising temperature hit his thoughts like a flamethrower caressing a snowflake.
'Say something!' said Cuddy.
Towers of intellect collapsed as the fire roared through Detritus' brain.
'Hey, look at this,' said one of the apprentices.
The inner walls of the warehouse were covered with numbers. Equations as complex as a neural network had been scraped in the frost. At some point in the calculation the mathematician had changed from using numbers to using letters, and then letters themselves hadn't been sufficient; brackets like cages enclosed expressions which were to normal mathematics what a city is to a map.
They got simpler as the goal neared – simpler, yet containing in the flowing lines of their simplicity a spartan and wonderful complexity.
Cuddy stared at them. He knew he'd never be able to understand them in a hundred years.
The frost crumbled in the warmer air.
The equations narrowed as they were carried on down the wall and across the floor to where the troll had been sitting, until they became just a few expressions that appeared to move and sparkle with a life of their own. This was maths without numbers, pure as lightning.
They narrowed to a point, and at the point was just the very simple symbol: '='.
'Equals what?' said Cuddy. 'Equals what?'
The frost collapsed.
Cuddy went outside. Detritus was now sitting in a puddle of water, surrounded by a crowd of human onlookers.
'Can't one of you get him a blanket or something?' he said.
A very fat man said, 'Huh? Who'd use a blanket after it had been on a troll?'
'Hah, yes, good point,' said Cuddy. He glanced at the five holes in Detritus' breastplate. They were at about head height, for a dwarf. 'Could you come over here for a moment, please?'
The man grinned at his friends, and sauntered over.
'I expect you can see the holes in his armour, right?' said Cuddy.
C. M. O. T. Dibbler was a survivor. In the same way that rodents and insects can sense an earthquake ahead of the first tremors, so he could tell if something big was about to go down on the street. Cuddy was being too nice. When a dwarf was nice like that, it meant he was saving up to be nasty later on.
'I'll just, er, go about my business, then,' he said, and backed away.
'I've got nothing against dwarfs, mind you,' said the fat man. 'I mean, dwarfs is practically people, in my book. Just shorter humans, almost. But trolls . . . weeeelll . . . they're not the same as us, right?'