Ram Odin took Noxon’s hand. “Are the mice all still attached to you?”

“Their little footprints are all over my body,” said Noxon. Then he sliced rapidly into the past.

Again, there was nothing to see—inside the starship, there were no observation windows. After a little while, though, the ship’s computers put up a display of the huge swath of Earth that was visible from their orbit about three hundred kilometers above the surface.

“It’s very white,” said Noxon. “Is it an unusually cloudy day?”

“We’re over the northern hemisphere,” said the expendable, “and we appear to be in a glacial maximum.”

“An ice age,” said Ram Odin. “Any idea which one?”

“There would be humans all over the place,” said the expendable. “Sapiens and Neanderthal, during the most recent one, but it was nearly a hundred thousand years long and so it’ll take a few passes to get a clear fix. And if it’s an earlier glacial maximum we’ll still have Homo erectus, and they got control of fire about half a million years ago.”

“The last ice age ended more than ten thousand years ago,” said Ram Odin to Noxon. “So you definitely took us a long way back.”

“I was aiming for at least eleven thousand years,” said Noxon. “Like when I followed a barbfeather’s path before you crashed nineteen starships into Garden.”

“Not me,” said Ram Odin. “It was a copy of me did all that.”

“What matters is that astronomical observations from this era aren’t going to be remembered and written down,” said the expendable. “But we still have to deal with the problem of concealment.”

Because the Moon was so large and strange to Noxon, and because it showed only one face to Earth, his first thought was to put the starship on the back side of it. But Ram Odin laughed out loud. “Humans had satellites going behind the Moon taking pictures long before this ship was built. And then there’s the little matter of half the moon getting sucked away.”

“So we can’t leave it anywhere in space,” said Noxon. “But it’s not as if we can lay it down on Earth, either. By the time this ship gets built, the surface of Earth will have been fully explored, won’t it?”

“Satellite photography even finds buried civilizations after thousands of years, by the traces of their irrigation ditches and house foundations,” said the expendable.

“So we can’t even bury the ship,” said Noxon.

“And the hull can’t withstand underwater pressures,” said Ram Odin. “So we can’t drop it into the ocean without risk of debris washing up on shore and getting discovered.”

“Even with the fields that protected it from impact with the surface of Garden?” asked Noxon.