The supply ships, coming and going far out in space, had been real enough; but the silver clouds that had hung for a lifetime above almost all the capitals of Earth had been an illusion. How it had been done, no one could tell, but it seemed that every one of those ships had been nothing more than an image of Karellen's own vessel. Yet it had been far more than a matter of playing with light, for radar had also been deceived, and there were still men alive who swore that they had heard the shriek of torn air as the fleet came in through the skies of Earth.

There was only the single ship now, hanging above New York. Indeed, as the world had just discovered, the ships above Man's other cities had never existed. The day before, the great fleet of the Overlords had dissolved into nothingness, fading like mists beneath the morning dew.

"This is the day!" whispered the radios in a hundred tongues. "This is the day!" said the headlines of a thousand newspapers. "This is the day!" thought the cameramen as they checked and rechecked the equipment gathered round the vast empty space upon which Karellen's ship would be descending.

"The ship is moving!" came the word, flashed instantly to every corner of the planet. "It is heading westward!"

It was not important; all that mattered was that Karellen no longer felt the need for this display of force. He had thrown away his psychological weapons.

At less than a thousand kilometres an hour, falling slowly down from the empty heights of the stratosphere, the ship moved out to the great plains and to its second rendezvous with history. It settled down obediently before the waiting cameras and the packed thousands of spectators, so few of whom could see as much as the millions gathered round their TV sets.

The ground should have cracked and trembled beneath that tremendous weight, but the vessel was still in the grip of whatever forces drove it among the stars. It kissed the earth as gently as a falling snowflake.

The curving wall twenty metres above the ground seemed to flow and shimmer: where there had been a smooth and shining surface, a great opening had appeared. Nothing was visible within it, even to the questing eyes of the camera. It was as dark and shadowed as the entrance to a cave.

"There are some children by the foot of the gangway. I would like two of them to come up and meet me."

There was silence for a moment. Then a boy and a girl broke from the crowd and walked, with complete lack of self-consciousness, towards the gangway and into history. Others followed, but stopped when Karellen's chuckle came from the ship. "Two will be enough."

Out of the orifice, a wide, glittering gangway extruded itself and drove purposefully towards the ground. It seemed a solid sheet of metal with hand-rails along either side. There were no steps; it was steep and smooth as a toboggan slide and, one would have thought, equally impossible to ascend or descend in any ordinary manner.

The world was watching that dark portal, within which nothing had yet stirred. Then the seldom-heard yet unforgettable voice of Karellen floated softly down from some hidden source. His message could scarcely have been more unexpected

Eagerly anticipating the adventure, the children -- they could not have been more than six years old -- jumped on to the metal slide. Then the first miracle happened.

It was a tribute to the Overlords' psychology, and to their careful years of preparation, that only a few people fainted. Yet there could have been fewer still, anywhere in the world, who did not feel the ancient terror brush for one awful instant against their minds before reason banished it forever.

A vast silence lay over the whole world for the space of twenty seconds -- though, afterwards, no one could believe that the time had been so short. Then the darkness of the great opening seemed to move forward, and Karellen came forth into the sunlight. The boy was sitting on his left arm, the girl on his right. They were both too busy playing with Karellen's wings to take any notice of the watching multitude.

Waving cheerfully to the crowds beneath, and to their anxious parents -- who, too late, had probably remembered the legend of the Pied Piper -- the children began swiftly ascending the steep slope. Yet their legs were motionless, and soon it was clear also that their bodies were tilted at right angles to that peculiar gangway. It possessed a private gravity of its own, one which could ignore that of Earth. The children were still enjoying this novel experience, and wondering what was drawing them upwards, when they disappeared into the ship.

There was no mistake. The leathery wings, the little horns, the barbed tail -- all were there. The most terrible of all legends had come to life, out of the unknown past. Yet now it stood smiling, in ebon majesty, with the sunlight gleaming upon its tremendous body, and with a human child resting trustfully on either arm.