'What is your name again?' said Tilden, aware that Vimes was the better starer. 'Keel,' said Vimes. 'John Keel.' And . . . what the hell. . . 'Look,' he said, 'you've only got one piece of paper there that means anything, and that's the report from that sergeant, assuming he can write.'

'As a matter of fact I have two pieces of paper,' said the captain. The other one concerns the death of John Keel, what?'

'What? For a scrap with the Watch?' In the current emergency, that would be quite sufficient for the death penalty,' said Tilden, leaning forward. 'But, ha, perhaps it won't be necessary in this case, because John Keel died yesterday. You beat him up and robbed him, what? You took his money but you didn't bother with the letters, because your sort can't read, what? So you wouldn't have known that John Keel was a policeman, what?'

'What?' Vimes stared at the skinny face with its triumphantly bristling moustache and the little faded blue eyes. And then there was the sound of someone industriously sweeping the floor in the corridor outside. The captain looked past him, growled, and hurled a pen. 'Get him out of here!' he barked. 'What's the little devil doing here at this time of night, anyway?' Vimes turned his head. There was a skinny, wizened-looking man standing in the doorway, bald as a baby. He was grinning stupidly, and holding a broom. 'He's cheap, sir, hnah, and it's best if he comes in when it's, hnah, quiet,' Snouty murmured, grabbing the little man by a stick-thin elbow. 'C'mon, out you get, Mister Lousy-' So now the crossbow wasn't pointing at Vimes. And he had several pounds of metal on his wrists or, to put it another way, his arms were a hammer. He went to stand up ... Vimes woke up and stared at the ceiling. There was a deep rumbling somewhere near by. Treadmill? Watermill? It was going to be a corny line, but some things you had to know. 'Where am I?' he said. And then he added: 'This time?'

'Well done,' said a voice somewhere behind him. 'Consciousness to sarcasm in five seconds!' The room was large, by the feel of the air, and the play of light on the walls suggested there were candles alight behind Vimes. The voice said: 'I'd like you to think of me as a friend.'

'A friend? Why?' said Vimes. There was a smell of cigarette smoke in the air. 'Everyone ought to have a friend,' said the voice. 'Ah, I see you've noticed you're still handcuffed-' The voice said this because in one movement Vimes had swung himself off the table and plunged forward- Vimes woke up and stared at the ceiling. There was a deep rumbling somewhere near by. Treadmill? Watermill? Then his thoughts knotted themselves most unpleasantly. 'What,' he said, 'just happened?'

'I thought you might like to try that again, lad,' said the invisible friend. 'We have little tricks here, as you will learn. Just sit up. I know you've been through a lot, but we don't have time for messing about. This is sooner than I'd like, but I thought I'd better get you out of there before it went really runny . . . Mister Vimes.' Vimes froze. 'Who are you?' he said. 'It's Lu-Tze officially, Mister Vimes. But you can call me Sweeper, since we're friends.' Vimes sat up carefully and looked around. The shadowy walls were covered with . . . writing, it must be writing, he thought, but the Hubland type of writing which is only one step away from being little pictures. The candle was standing on a saucer. Some way behind it, just visible in the shadows, were two cylinders, each as wide as a man and twice as long, set in massive horizontal bearings, one above the other. Both were turning slowly, and both gave the impression of being a lot bigger than their mere dimensions suggested. Their rumble filled the room. There was a strange violet haze around them. Two yellow-robed figures tended the cylinders, but Vimes's eye was drawn to the skinny little bald man sitting on an upturned crate by the candle. He was smoking a foul roll-up of the sort favoured by Nobby, and looked like a foreign monk. In fact, he looked exactly the kind Vimes occasionally saw with begging bowls in the street. 'You're looking fit, Mister Vimes,' said Sweeper. 'You were in the Watch House, right?' said Vimes. 'Snouty called you Lousy!'

'Yes, Mister Vimes. Lu-Tze. I've been sweeping up there every night for the past ten days. All for two pence and all the kicks I can't dodge. Just waiting for you.'

'And you told Rosie Palm where I'd gone, too? You were the monk on the bridge?'

'Right again. Couldn't be sure she'd catch up.'

'How do you know who I am?'

'Don't get excited, Mister Vimes,' said Sweeper calmly. 'I'm here to help you . . . your grace. And I'm your friend because right now I'm the only person in the world who will probably believe anything you tell me about, oh, thunderstorms and falls, that sort of thing. At least,' he added, 'the only sane person.' He watched Vimes as the man sat quite still for half a minute. 'Good, Mister Vimes,' said Sweeper. Thinking. I like that in a man.'

'This is magic, right?' said Vimes, at last. 'Something like that, yes,' said Sweeper. 'F'rinstance, just now we moved you back in time. Just a few seconds. Just so you wouldn't do anything you'd regret. Can't say I blame you for wanting to have a go at someone after all you've been through, but we don't want any harm to come to you, do we . . .'

'Hah? I almost had my hands round your throat!' Sweeper smiled. It was a disarming little smile. 'Smoke?' he said. He fumbled in his robe and produced a ragged hand-rolled cigarette. 'Thanks, but I've got my own-' Vimes began automatically. His hand stopped halfway to his pocket. 'Oh, yes,' said Sweeper. The silver cigar case. Sybil gave it to you as a wedding present, right? Shame about that.'

'I want to go home,' said Vimes. It came out as a whisper. He hadn't been sleeping in the past twelve hours, merely recovering. This time it was Sweeper who sat in silence, apart from the rumble of the cylinders. 'You're a policeman, Mister Vimes,' he said eventually. 'Well, I'd like you to believe, for a while, that I'm a sort of policeman too, all right? Me and my colleagues, we see that . . . things happen. Or don't happen. Don't ask questions right now. Just nod.' Vimes shrugged instead. 'Good. And let's say on our patrol we've found you, as it might be, in a metaphorical kind of way, lying in the gutter on a Saturday night singing a rude song about wheelbarrows-'

'I don't know a rude song about wheelbarrows!' Sweeper sighed. 'Hedgehogs? Custard? One-string fiddles? It really doesn't matter. Now, we've found you a long way from where you should be and we'd like to get you home, but it's not as easy as you might think.'

'I've gone back in time, haven't I? It was that bloody Library! Everyone knows the magic in there makes strange things happen!'

'Well, yes. It was mainly that, yes. It's more true to say that you, er, got caught up in a major event.'

'Can anyone get me back? Can you get me back?'

'We-ell. . .' said Sweeper, looking awkward. 'Wizards can if you can't,' said Vimes. 'I'll go back and see them in the morning!'

'Oh, you will, will you? I'd like to be there when you do. These ain't the wizards under decent old Ridcully, you know. You'll be lucky if they only laugh at you. Anyway, even if they wanted to be helpful they'd hit the same problem.'

'And what's that?'

'It can't be done. Not yet.' For the first time in the conversation Sweeper looked ill at ease. 'The big problem I'm facing, Mister Vimes, is that I ought to tell you a few things that I'm not, in any circumstances, allowed to tell you. But you're a man who isn't happy until he knows the facts. I respect that. So ... if I tell you everything, can you spare me, oh, twenty minutes of your time? It could save your life.'

'All right,' said Vimes. 'But what-'

'You've got a bargain,' said Sweeper. 'Roll 'em, boys.' The noise of the big cylinders changed for a moment and Vimes felt a very slight shock, a suggestion that his whole body had just gone plib. 'Twenty minutes,' said Sweeper. 'I'll answer every question. And then, Mister Vimes, we'll send you back from twenty minutes in the future to now and you'll tell yourself what you and me agree you ought to know. Which will be most of it, really. You're a man who can keep secrets. Okay?'

'Yes, but-' Vimes began. The tone of the spinning cylinders changed slightly. Sam Vimes saw himself standing in the middle of the room. 'That's me!'

'Yeah, right,' said Sweeper. 'Now listen to the man.'

'Hello, Sam,' said the other Vimes, staring not quite at him. 'I can't see you, but they say you can see me. Remember the smell of lilac? You thought about those who died. And then you told Willikins to hose down that kid. And, eh ... you've got a pain in your chest you're a bit worried about but you haven't told anyone . . . That's about enough, I think. You know I'm you. Now, there's some things I can't tell you. I can know 'em because I'm in a-' The speaker stopped and looked away, as if he was taking instruction from someone offstage '-a closed loop. Er, you could say I'm twenty minutes of your life you don't recall. Remember when you had . . . a sensation that his whole body had just gone plib.

Sweeper stood up. 'I hate to do this,' he said, 'but we're in the temple and we can pretty much dampen out the paradoxes. On your feet, Mister Vimes. I'm going to tell you everything.'

'You just said you couldn't!' Sweeper smiled. 'Need any help with those handcuffs?'

'What, these old Capstick Mark Ones? No, just give me a nail and a couple of minutes. How come I'm in a temple?'

'I brought you here.'

'You carried me?'

'No. You walked with me. Blindfolded, of course. And then when you were here, I gave you a little drink . . .'

'I don't remember that!'

'Of course not. That was the purpose of the drink. Not very mystical, but it does the job. We don't want you coming back here, now, do we? This place is supposed to be a secret-'

'You messed up my memory? Now you see here-' Vimes half stood, but Sweeper held up his hands placatingly. 'Don't worry, don't worry, it just . . . made you forget a few minutes,' he said. 'How many minutes?'

'Just a few, just a few. And it had herbs in it. Good for you, herbs. And then we let you sleep. Don't worry, no one is after us. They'll never know you've gone. See this thing here?' Sweeper picked up an open-work box that lay beside his chair. It had straps like a knapsack, and Vimes could just see a cylinder inside the box. 'This is called a Procrastinator,' said the monk, 'and it's a tiny version of the ones over there, the ones that look like your granny's mangle. I'm not going to get technical, but when it's spinning it moves time around you. Did you understand what I just said?'

'No!'

'All right, it's a magic box. Happier?'

'Go on,' said Vimes grimly. 'You wore one of these when I led you here from the Watch House. Because you were wearing it, you were, shall we say, outside time. And after we've had this little talk I'll take you back to the Watch House and the old captain won't know any different. No time is passing in the outside world while we're in the temple. The Procrastinators take care of that. Like I said, they move time around. Actually, what's really happening is that they are moving us back in time at the same time that time moves us

forward. We've got others around the place. Good for keeping food fresh. What else can I tell you . . . oh, yeah. It helps keep track if you just think of things happening one after another. Believe me.'

'This is like a dream;' said Vimes. There was a clink as the handcuffs sprang open. 'Yes, it is, isn't it,' said Sweeper calmly. 'And can your magic box take me home? Move me in time all the way to where I ought to be?'

'This? Hah. No, this is strictly for small-scale stuff-'

'Look, Mr Sweeper, I've spent the last day fighting a right bastard on a roof and getting beaten up twice and sewn up once and, hah, stitched up, too. I've got the impression I should be thanking you for something but I'm damned if I know what it is. What I want is straight answers, mister. I'm the Commander of the Watch in this city!'