the thoughts had been dead ends.

One could write a natural history of the Pleistocene, complete with photographs and sketches, and it would be a pointless thing to do, because no future scientist would ever have a chance to read it.

Or they might labor to build a memorial, a vast pyramid, perhaps, which would carry a message forward across fifteen hundred centuries, snatching with bare hands at a semblance of immortality. But if they did, they would be working against the sure and certain knowledge that it all would come to naught, for they knew in advance that no such pyramid existed in historic time.

Or they might set out to seek contemporary Man, hiking across four thousand miles of wilderness to Bering Strait and over into Asia. And having found contemporary Man cowering in his caves, they might be able to help him immeasurably along the road to his great inheritance. Except that they'd never make it and even if they did, contemporary Man undoubtedly would find some way to do them in and might eat them in the bargain.

They came out of the woods and there was the cabin, just a hundred yards away. It crouched against the hillside above the spring, with the sweep of grassland billowing beyond it to the slate-gray skyline. A trickle of smoke came up from the chimney and they saw the door was open.

"Wes oughtn't to leave it open that way," said Cooper. "No telling when a bear might decide to come visiting."

"Hey, Wes!" yelled Hudson.

But there was no sign of him.

Inside the cabin, a white sheet of paper lay on the table top. Hudson snatched it up and read it, with Cooper at his shoulder.