This was the Loom, as he and Ben had come to call it, a machine of electromechanics and human flesh which – so they believed, so their theories indicated – could be used to change the warp and weft of the tapestry of time itself. And yet none of it was his, Rory's. Not the Vannevar Bush Analyser which was being loaned to the two of them by MIT; they were students of the Institute of Advanced Studies at Princeton, and they had come here to Cambridge ostensibly to run complex relativistic models with the Analyser. Not the dreaming boy himself – and still less the contents of his head. All that Rory O'Malley owned was the will, to bring these components together, to make it so.

Rory pulled a lock of black hair back from Ben's brow. He wore it too long, Rory thought. Ben didn't stir, and Rory wasn't surprised. The sleeping draught he had poured into Ben's midnight coffee was strong enough to ensure that. Ever since their time together serving in the International Brigade in Spain Rory had always been fond of Ben, poor, deep, intense Ben. But he needed him too, or at least the peculiar abilities locked up in that head of his. Rory saw no great contradiction in this mixture of manipulation and affection. He was intent after all on nothing less than a cleansing of history, a reversal of the greatest crime ever committed. What was a little subterfuge compared to that?

He pulled a scrap of paper from his jacket pocket. It bore a poem of sixteen lines in English, translated roughly into Latin. He scanned it one last time. This was the core of his project, a mandate to history laden with all the meaning and purpose he could cram into it. Now these words would be sent out into the cosmos, crackling along Godel's closed timelike curves like Morse dots and dashes on a telegraph wire – all the way from the future to the past, where some other dreaming head would receive it. All he had to do was to read to Rory, read out the Godel trajectories computed by the Analyser, read the bit of doggerel. That was all, like reading to a child. And everything would change.