“Theoretically,” said the expendable. “But we’ve been in an atom-for-atom lock with the structural components of the outbound ship. The energy cost of breaking away might be too high. We don’t understand the nature of those bonds, since they’ve never been detected or measured in nature. Nor can we be sure in which direction Earth might lie. Or how far we’ve traveled in relation to it.”

“Clear enough answer,” said Noxon, who understood little of the physics but knew what “probably not” sounded like when he heard it.

“The new plan is obvious,” said a mouse.

“The mice think it’s obvious,” said Noxon.

“The mice can come live in my butt,” said Ram Odin.

“No need to be crude,” said a mouse.

“He’s being hospitable,” said another.

“What’s your obvious plan?” asked Noxon.

“Slice onward until the time when they haven’t yet started constructing the outbound ship.”

The expendable heard this, too, of course, and immediately began working it out. “Looking at the ship’s memory, which includes all the reports on the construction process, the ship was finished on—”

“No,” said Noxon. “We need a time when there was nothing in the space we occupy, but there were people up here so I can attach to their paths.”

“If it’s at all possible,” said Ram Odin, “can you seek out a time, about twenty-five years, when there were no paths at all, and choose a path before that break?”

“Why?” asked Noxon. “What’s the gap?”

“The comet that came so close it threw the Moon out of its orbit. Tidal forces then tore chunks out of the Moon, which formed a ring that destroyed everything that was orbiting Earth. I’d really like us not to reappear during that time. And before it would be better than after.”

“Why? Either way, we’ll be seen.”

“I don’t want you to be disappointed in the dingy little runt of a Moon we have left,” said Ram Odin. “You need to see the glorious Moon under whose influence the human species evolved.”

“I’m pretty sure I’ll see both versions of the Moon, if this works at all,” said Noxon. “So here’s what I’ll do. I’ll take us forward to a time before this ship was built. Then I’ll attach to a forward-moving path out here in space. I’ll switch the whole ship to that timeflow. If it works, then I’ll immediately jump us further into the past without looking for a path at all.”

“I thought you couldn’t do it without a path.”