ildren
came. Perhaps their elders had foreseen it in time to take some
measures, which would be the children's ship. But that ship had been
built very hastily. It could have been begun before the bombardment
started, or it could have been completed only near the end, when
asteroids already plunged into defenseless Earth and it heaved and
writhed in agony.

Humans caught in such a cosmic trap would be in no mood to negotiate or
make promises, if any sort of beachhead to the future could be set up.
They would pour through and the world of the present must simply
dissolve into incoherence. There could be no peace. It was unthinkable.

* * * * *

The investigation-team from the East arrived to learn from Soames all
about the landing of the ship.

He told them, giving them the tape from the wave-guide radar and
speaking with strict precision of every event up to the moment of his
arrival at Gissell Bay with the children and their artifacts. He did not
mention telepathy or time-travel because they seemed so impossible.

When the military men wanted information about instantly available
super-weapons, he told them that he knew nothing of weapons. They'd have
to judge from the gadgets the children had brought. When the
public-relations men asked briskly from what other planet or solar
system the spaceship had come, and when a search-ship might be expected,
looking for the children, he was ironic. He suggested that the children
might give that information if asked in the proper language. He didn't
know it. But the two physicists were men whose names he knew and
respected. They listened to what he said. They'd look at the devices
from the ship and then come back and talk to him.

He went back to his brooding. The children had travelled through time.
Everything pointed to it, from the meteor-watch radar to the children's
reaction at sight of the pock-marked moon and their knowledge that
there should have been a Fifth Planet, to which they assigned four
moons. It had happened. Positively. But there was one small difficulty.
If time-travel were possible, a man travelling about in the past might
by some accident kill his grandfather, or his father, in which case he
could not be born, and hence could not possibly go back in time. But if
he did not go back in time he would be born and could face the
possibility of preventing his own existence--if time-travel was
possible. But this was impossible, s