The sun was blazing from a cloudless sky as he shouldered his pack and unlocked the massive gates. Even ten years ago packs of starving dogs had hunted in this area, and though he had seen none for years he was still cautious and always carried a revolver when he went into the open.

The sunlight was so brilliant that the reflected glare hurt his eyes; but it was almost wholly lacking in heat. Although the belt of cosmic dust through which the Solar System was now passing had made little visible difference to the sun’s brightness, it had robbed it of all strength. No one knew whether the world would swim out into the warmth again in ten or a thousand years, and civilization had fled southward in search of lands where the word “summer” was not an empty mockery.

The latest drifts had packed hard and Professor Millward had little difficulty in making the journey to Tottenham Court Road. Sometimes it had taken him hours of floundering through the snow, and one year he had been sealed in his great concrete watch tower for nine months.

He kept away from the houses with their dangerous burdens of snow and their Damoclean icicles, and went north until he came to the shop he was seeking. The words above the shattered windows were still bright: “Jenkins Sons. Radio and Electrical. Television A Speciality.”

Some snow had drifted through a broken section of roofing, but the little upstairs room had not altered since his last visit a dozen years ago. The all-wave radio still stood on the table, and empty tins scattered on the floor spoke mutely of the lonely hours he had spent here before all hope had died. He wondered if he must go through the same ordeal again.

Professor Millward brushed the snow from the copy of The Amateur Radio Handbook for 1965, which had taught him what little he knew about wireless. The test-meters and batteries were still lying in their half-remembered places, and to his relief some of the batteries still held their charge. He searched through the stock until he had built up the necessary power supplies, and checked the radio as well as he could. Then he was ready.