'What's P?'

'That may be the wrong sort of question.'

'When I was a little girl it was just a magic box,' Adora Belle broke in, in a dreamy voice. 'It was in a much smaller room and when it unfolded a few times there was a box with a golem's foot in it.'

'Ah, yes, in the third iteration,' said Ponder. 'They couldn't get much further than that in those days. Now, of course, we've got controlled recursion and aim-driven folding that effectively reduces collateral boxing to 0.13 per cent, a twelvefold improvement in the last year alone!'

'That's great!' said Moist, feeling that it was the least he could do.

'Does Miss Dearheart want to see the item again?' said Ponder, lowering his voice. Adora Belle still had a faraway look in her eyes.

'I think so,' said Moist. 'She's very big on golems.'

'We were about to fold up for today in any case,' said Ponder. 'It won't hurt to pick up the Foot on the way'

He took a large megaphone from a bench and held it to his lips.

'THE CABINET CLOSES IN THREE MINUTES, GENTLEMEN. ALL RESEARCHERS INSIDE THE SAFETY AREA NOW, PLEASE. BE THERE OR BE SQUARE!'

'Be there or be square?' said Moist, as Ponder lowered the megaphone.

'Oh, a couple of years ago someone ignored the warning and, um, when the Cabinet folded up he temporarily became a curiosity'

'You mean he ended up inside a fourteen-inch cube?' said Moist, horrified.

'Mostly. Look, we really would be very happy if you didn't tell anyone about the Cabinet, thank you. We know how to use it, we think, but it might not be the way it was intended to be used. We don't know what it's for, as you put it, or who built it or even if they are completely the wrong questions to ask. Nothing in it is bigger than about fourteen inches square, but we don't know why this is or who it is who decides they are curious, or why, and we certainly don't know why it contains nothing pink. It's all very embarrassing. I'm sure you can keep a secret, Mr Lipwig?'

'You'd be amazed.'

'Oh? Why?'

'That's the wrong kind of question.'

'You do know something quite important about the Cabinet,' said Adora Belle, apparently waking up. 'You know it wasn't built for or by a girl between the ages of four and, oh, eleven years old.'

'How do we know that?'

'No pink. Trust me. No girl in that age group would leave out pink.'

'Are you sure? That's wonderful!' said Ponder, making a note on his clipboard. 'That's certainly worth knowing. Let's get the Foot, then, shall we?'

The broomstick-riding wizards had touched down now. Ponder cleared his throat and picked up the megaphone. 'ALL DOWN? WONDERFUL. HEX — BE SO GOOD AS TO FOLD, PLEASE!'

There was silence for a while, and then a distant clattering noise began to grow, up near the ceiling. It sounded like gods shuffling wooden playing cards that happened to be a mile high.

'Hex is our thinking engine,' said Ponder. 'We'd hardly be able to explore the box at all without him.'

The clattering was becoming louder and faster.

'You might find your ears aching,' said Ponder, raising his voice. 'Hex tries to control the speed, but it takes finite time for the ventilators to get air back into the room. THE VOLUME OF THE CABINET CHANGES VERY FAST, YOU SEE!'

This was shouted against the thunder of collapsing drawers. They slammed in on themselves far too fast for the human eye to follow as the edifice shrank and folded and slid and rattled down into house size, shed size and, finally, in the middle of the huge space — unless it was some kind of time — became a small polished cabinet, about a foot and a half on a side, standing on four beautifully carved legs.

The Cabinet's doors clicked shut.

'Slowly unfold to specimen 1,109,' said Ponder, in the ringing silence.

The doors opened. A deep drawer slid out.

It went on sliding.

'Just follow me,' said Ponder, strolling towards the Cabinet. 'It's fairly safe.'

'Er, a drawer about a hundred yards long has just slid out of a box about fourteen inches square,' said Moist, in case he was the only one to notice.

'Yes. That's what happens,' said Ponder, as the drawer slid back about halfway. Its side, Moist saw, was a line of drawers. So drawers opened… out of drawers. Of course, Moist thought, in eleven-dimensional space that was the wrong thing to think.

'It's a sliding puzzle,' said Adora Belle, 'but with lots more directions to slide.'

'That is a very graphic analogy which aids understanding wonderfully while being, strictly speaking, wrong in every possible way,' said Ponder.

Adora Belle's eyes narrowed. She had not had a cigarette for ten minutes.

The long drawer extruded another drawer at right angles. All along the sides of it were, yes, yet more drawers. One of these extended slowly.

Moist took a risk, and tapped on what appeared to be perfectly ordinary wood. It made a perfectly ordinary noise. 'Should I worry that I just saw a drawer slide through another drawer?' he said.

'No,' said Ponder. 'The Cabinet is trying to make four-dimensional sense of something that is happening in eleven or, possibly, ten dimensions.'

'Trying? Do you mean it's alive?'

'Aha! The right type of question!'

'I bet you don't know the answer, though.'

'You are correct. But you must admit it's an interesting question not to know the answer to. And, yes, here we have the Foot. Hold and collapse, please, Hex.'

The drawers collapsed back into themselves in a series of crashes, much shorter and less dramatic than before, leaving the Cabinet looking demure and antique and slightly bow-legged. It had little claws as feet, a cabinet-makers' affectation that always annoyed Moist in a low-grade way. Did they think the things moved around in the night? Or maybe the Cabinet really did.

And the Cabinet's doors were open. Nestling inside, and only just fitting, was a golem's foot, or at least most of one.

Once, golems were beautiful. Once, the very best sculptors probably made them to rival the most beautiful of statues, but long since then the fumble-fingered many who could barely make a snake out of clay found that bashing the stuff into the shape of a big hulking gingerbread man worked just as well.

This foot was one of the early kind. It was made of a clay-like white china, with patterns of tiny raised markings in yellow, black and red. A little brass plate in front of it was engraved in Uberwaldian: 'Foot of Umnian Golem, Middle Period.'

'Well, whoever made the Cabinet comes from—'

'Anyone looking at the label sees it in their native tongue,' said Ponder wearily. 'The markings apparently indicate that it did indeed come from the city of Um, according to the late Professor Head.'

'Um?' said Moist. 'Um what? They weren't sure what to call the place?'

'Just Um,' said Ponder. 'Very ancient. About sixty thousand years, I believe. Back in the Clay Age.'

'The first golem-makers,' said Adora Belle. She unslung the bag and started to rummage in the straw.

Moist tapped the foot. It seemed eggshell thin.

'It's some sort of ceramic,' said Ponder. 'No one knows how they made it. The Umnians even baked boats out of the stuff.'

'Did they work?'

'Up to a point,' said Ponder. 'Anyway, the city was totally destroyed in the first war with the ice giants. There's nothing there now. We think that the foot was put in the Cabinet a long time ago.'

'Or will be dug up some time in the future, perhaps?' said Moist.

'That could very well be the case,' said Ponder gravely.

'In which case, won't that be a bit of a problem? I mean, can it be in the ground and in the Cabinet at the same time?'

'That, Mr Lipwig, is—'

'The wrong type of question?'

'Yes. The box exists in ten or possibly eleven dimensions. Practically anything may be possible.'