beside her as she rode. He was convinced that he
wouldn't leave her side while Dillon was around. But even as he knew
that desperate certitude, he was filled with confusion and a panicky
uncertainty.

When they'd traveled about half a mile, another frightening thought
occurred to Coburn. Perhaps Dillon--passing for human--wasn't alone.
Perhaps there were thousands like him.

Invaders! Usurpers, pretending to be men. Invaders, obviously, from
space!

II

They made eight miles. At least one mile of that, added together, was
climbing straight up. Another mile was straight down. The rest was
boulder-strewn, twisting, donkey-wide, slanting, slippery stone. But
there was no sign of anyone but themselves. The sky remained
undisturbed. No planes. They saw no sign of the raiding force from
across the border, and they heard no gunfire.

Coburn struggled against the stark impossibility of what he had seen.
The most horrifying concept regarding invasion from space is that of
creatures who are able to destroy or subjugate humanity. A part of that
concept was in Coburn's mind now. Dillon marched on ahead, in every way
convincingly human. But he wasn't. And to Coburn, his presence as a
non-human invader of Earth made the border-crossing by the Bulgarians
seem almost benevolent.

They went on. The next hill was long and steep. Then they were at the
hill crest. They looked down into a village called Naousa. It was larger
than Ardea, but not much larger. One of the houses burned untended.
Figures moved about. There were tanks in sight, and many soldiers in the
uniform that looked dark-gray at a distance. The route by which Dillon
had traveled had plainly curved into the line-of-march of the Bulgarian
raiding force.

But the moving figures were not soldiers. The soldiers were still. They
lay down on the grass in irregular, sprawling windrows. The tanks were
not in motion. There were two-wheeled carts in sight--reaching back
along the invasion-route--and they were just as stationary as the men
and the tanks. The horses had toppled in their shafts. They were
motionless.

The movement was of civilians--men and women alike. They were Greek
villagers, and they moved freely among the unmilitarily recumbent
troops, and even from this distance their occupation was clear. They
were happily picking the soldiers' pockets. But there was one figure
which moved from one prone figure to another much too quickly to be
looting. Coburn saw su