resulting from facing real or imaginary danger.

Barring space collision or an accident on a world they were exploring,
nothing could happen to them.

"We checked the air, took soil and vegetation samples, before we
landed," Thompson said. "There is nothing here that is harmful to a
human." There was comfort in the thought.

Kurkil brightened perceptibly. "But, what happened to the race that
built this city?"

"I don't know," Thompson answered. A tinge of gruffness crept into his
voice as he forced out of his mind the memories of what they had seen in
this building they had entered and had climbed. This had once been an
office building, a place where the unknown people who had worked here
had handled their business transactions and had kept their records. They
had seen no bookkeeping machines, none of the elaborate mechanical
devices used in Sol Cluster to record the pulse of commerce. This race
had not progressed that far. But they had left behind them books written
in an unintelligible script, orders for merchandise still neatly
pigeonholed, all in good order with no sign of disturbance.

The workers might have left these offices yesterday, except for the
carpets of dust that covered everything.

"There isn't even any animal life left," Kurkil spoke.

"I know."

"But what happened? A race that has progressed to the city-building
stage doesn't just get wiped out without leaving some indication of what
happened to them."

"Apparently they did just that."

"But it's not possible."

"It happened."

"But--"

"There's Neff," Thompson spoke. Far down the avenue below them, three
figures had appeared, Neff, Fortune, and Ross. Neff tall and slender,
Fortune round like a ball, and Ross built square like a block of
concrete. Neff saw them on top of the building and beckoned to them.
There was urgency in the gesture.

"They've found something," Thompson said. With Kurkil following him he
went hastily out of the building.

"What is it?"

"Come and see," Neff answered. Neff's face was gray. Fortune and Ross
were silent.

The building in front of which they were standing had been a house once.
The architecture resembled nothing they had ever seen on Earth but the
purpose of the structure was obvious. Here somebody had lived. Thompson
tried to imagine people living here, the husband coming home in the
evening to the dinner prepared by the wife, kids running to meet him.
His imagination failed.

"Back here,