Wizards have a wonderful turn of speed.
Ponder and the Dean reached the Great Hall in twelve seconds, the Dean slightly in the lead. The ball of rainbows had got there before them, though, and hung high over the black and white flagstones of the floor.
The hall was packed with wizards. Teams had been sent out to the furthest corners of the university, which were pretty far. Space and time had long ago been warped by the ancient magical stones, and there were wizards at UU who had happily occupied nooks and corners for decades or longer, regarding the Great Hall and surrounding buildings as the colonists on some faraway continent might regard the ancient mother country. Distant studies had been broken into and their occupants dragged out or, in some unfortunate cases, swept up. Wizards that Ponder had never seen before were in the throng, blinking in the light of common day.
Panting slightly, Ponder hurried over to Ridcully.
`You said you wanted a map, sir,' he said.
`Yes, Stibbons. Can't plan a campaign without a map!'
`Then look up now, sir! Here it comes!'
The air wavered for a moment, and then the mated rainbows gave birth. Frozen streamers of light looped through the hazy air of the hall. They twisted and tangled and curved in ways that suggested more than the everyday four dimensions were involved.
`Looks very pretty,' said the Archchancellor, blinking. 'Er ...'
`I thought it would help us sort out further nodalities,' said Ponder.
`Ah yes, good idea,' said Ridcully. `No one wants unsorted nodalities.' The other senior wizards nodded sagely.
`By which I mean,' Ponder added, `it will show us those points where our intervention will have been going to be was essential, if I can put it that way.'
`Oh,' said the Archchancellor. `Er ... what does the coloured line mean, exactly?'
`Which one, sir?'
`All of them, man!'
`Well, the points of intervention that require a human show up as red circles. Those that can be left to Hex are white. The blue lines represent the author of, ahem, The Ology, the yellow lines is the optimum path for the author of The Origin, and the green line represent slippage between futures. Known thaumic occlusions are purple, but I expect you worked that out already.'
`What's that one?' said the Dean, pointing to a red circle with his staff.
`We must make certain he doesn't get off the boat at an island called Tenerife,' said Ponder. `Seasickness again, you see. Quite a few Darwins got off there.'
The tip of the staff moved. `And that one?'
`He must get off the boat at the island of St Jago. He has valuable insights there.'
`Sees things evolvin', that kind of thing?' said Ridcully.
`No, sir. You can't see things evolving, even when they're doing it.' `We saw them on Mono Island,' said the Lecturer in Recent Runes.
`You could practically hear them!'
`Yes, sir. But we have a god of evolution. Gods aren't patient. On Roundworld, evolution takes time. Lots of time. Darwin was raised in the belief that the Roundworld universe was created in six days -'
`Which is correct, as I have pointed out,' said the Dean proudly.
`Yes,' said Ponder, `but I have also pointed out that on the inside it took billions of years. It is vital that Darwin realises that evolution has got lots of time to work in.'
Before the Dean could protest, Ponder turned back to the shining, twisting tangle of light.
'There is where the mast falls on his head in the port of Buenos Aires,' he said, pointing. `The Beagle was shot at. It was meant to he a blank, fired from a cannon, but for some reason it had been loaded. The British were very upset about it, and issued a stern diplomatic protest by sending a warship to bombard the port to rubble. This one is where Darwin bludgeons himself into unconsciousness with his own bolas in Argentina. This one is where he's severely injured putting down an insurrection-'
`He got about a bit for a man who collected flowers and things,' said Ridcully, with a touch of admiration.
`Look, I've been thinking about all this,' said the Dean. `This "science" is all about the search for truth, yes? Why don't we just tell them the truth?'
`You mean tell them that their universe was accidentally started by you, Dean, sticking your hand into some raw firmament created to use up spare power from the thaumic reactor?' said Ridcully.
`Put like that it seems a bit unlikely, I admit, but-'
`No direct contact, Dean, we agreed about that,' said Ridcully. `We just clear his way. What's that nodality, Stibbons? It's flashing.'
Ponder looked at where the Archchancellor's staff was pointing.
`That's a tricky one, sir. We will have to ensure that Edward Lawson, a British official in the Galapagos Islands, isn't struck by a meteorite. It's a new malignity, Hex says. In a number of histories, it happens a few days before he meets Darwin. Remember, sir? I mentioned it in my yellow folder that was delivered to your office this morning.' Ponder sighed. `He draws Darwin's attention to some interesting facts.'
`Ah, I read that one,' said Ridcully, his happy tone indicating that this was a lucky coincidence. `Darwin seemed to be too busy runnin' around like a monkey in a banana plantation to spot the clues, eh?'
`It would be true to say that his full theory of natural selection was evolved on mature reflection some time after his voyage, yes,' said Ponder, carefully answering a slightly different question.
`And this chap Lawson was important?'
`Hex believes so, sir. In a way, everyone Darwin met was important. And everything he saw.'
`And then whoosh, this chap was hit by a rock? I call that suspicious.'
`Hex does too, sir.'
`I'll be jolly glad when we've got this Darwin to the damn islands, then,' said the Archchancellor. `We'll need a holiday after this. Oh well, I'll address the wizards now. I hope we'll have enough for-'
`Er, we haven't just got to get him to the islands. We've got to get him all the way home, sir,' said Ponder. `He'll be away from home for nearly five years.'
`Five years?' said the Dean. `I thought visiting the wretched islands was what it was all about!'
`Yes and then again, in a very real sense, no, Dean,' said Ponder. `It would be more correct to say they later became what it was all about. He was actually there for a little more than a month. It was a very long voyage, sir. They went all around the world. I'm sorry, I hadn't made that clear. Hex, show the entire timelines, please.'
The display began to recede, drawing from nowhere more and more tangles and loops, as if half a dozen cosmic kittens had been given stars to play with instead of balls of wool. There was a gasp from the throng of wizards.
The tangles were still streaming away overhead when the Dean said: `There's millions of the wretched things!'
`No, Dean,' said Ponder. `It looks like that, but there are only 21,309 important nodalities at this point. Hex can deal with almost all of them. They involve quite minute changes at the quantum level.'
The wizards continued to stare upwards as the whorls and loops flashed by and dwindled.
`Someone really doesn't want that book,' said the Lecturer in Recent Runes, his face illuminated by the multi coloured glow.
`In theory there isn't a someone in charge,' said Ponder.
`But the odds against Darwin writing Origin are getting bigger by the minute!'
`The odds against anything actually happening are huge, when you come to think about it,' said Ridcully. `Take poker, for example. The odds against four aces are huge, but the odds of having any four cards at all are really big.'
`Well put, Archchancellor!' said Ponder. `But this is a crooked game.'
Ridcully strode out into the centre of the Great Hall, his face illuminated by the glowing map.