Three hundred feet below, the broken sea of snow-covered roofs lay bathed in the bitter moonlight. Miles away the tall stacks of Battersea Power Station glimmered like thin white ghosts against the night sky. Now that the dome of St Paul’s had collapsed beneath the weight of snow, they alone challenged his supremacy.

Professor Millward walked slowly back along the bookshelves, thinking over the plan that had formed in his mind. Twenty years ago he had watched the last helicopters clilmb-ing heavily out of Regent’s Park, the rotors churning the ceaselessly falling snow. Even then, when the silence had closed around him, he could not bring himself to believe that the north had been abandoned forever. Yet already he had waited a whole generation, among the books to which he had dedicated his life.

In those early days he had sometimes heard, over the radio which was his only contact with the south, of the struggle to colonize the now-temperate lands of the Equator. He did not know the outcome of that far-off battle, fought with desperate skill in the dying jungles and across deserts that had already felt the first touch of snow. Perhaps it had failed; the radio had been silent now for fifteen years or more. Yet if men and machines were indeed returning from the north—of all directions—he might again be able to hear their voices as they spoke to one another and to the lands from which they had come.

Professor Millward left the University building perhaps a dozen times a year, and then only through sheer necessity. Over the past two decades he had collected everything he needed from the shops in the Bloomsbury area, for in the final exodus vast supplies of stocks had been left behind through lack of transport. In many ways, indeed, his life could be called luxurious: no professor of English literature had ever ceen clothed in such garments as those he had taken from an Oxford Street furrier’s.