“So what?” asked Rigg-the-killer. “They’re moving backward in time. Even when we jump around, at the end of a jump we’re still moving forward in time, the same direction as the rest of the universe. And the backward movement of the ship or ships would exactly duplicate the forward voyage of the ship coming here, so we’d still be inside the ship that voyaged out. We’ll never be able to find the backward-moving ship. Or ships.”

“Not with the skill set we’ve had up to now,” said Rigg Noxon. “But what if we could learn to go the other direction?”

“What if we could jump straight to Earth without using any starship at all?” asked Rigg-the-killer. “Because we can’t. There’s no reason to think we can.”

“I think Param holds the key,” said Rigg Noxon.

“She slices time very thin, but she still moves forward in time.”

“Because all she knew was slicing,” said Rigg Noxon. “She couldn’t jump forward or backward, the way we can. Now, with our facemasks, we can slice time the way she does. We can see those tiny divisions and do something about them. But we can also jump backward. We can slice time backward.”

“We’re still moving forward,” said Rigg-the-killer. “Between slices.”

“So what?” asked Noxon. “If we slice time thin enough, and we jump backward two nanoseconds, stay there for one nanosecond, and then jump backward another two nanoseconds, the effect is that we move backward in time at the rate of one nanosecond per nanosecond, which is the same rate that the back-traveling ship will be moving backward through time.”

“But when we’re in existence, we’re going forward,” Rigg-the-killer insisted. “No matter how fine you chop the time.”

“Maybe you’re right,” said Noxon. “But you’re forgetting the very first thing we ever did. We saw a path, Umbo slowed it down for us, and we latched on. That was how we jumped, by latching on to a person. If we can at least detect a backward-­moving person’s path, we can attach and it will change our direction.”

“Or maybe not,” said Rigg. “Maybe forward-time and backward-­time annihilate each other when they touch, like matter and anti-matter.”

“So I’ll do it alone,” said Noxon. “I’m the extra copy, right? So if I get annihilated, we’re back to the right number of Riggs, that’s all.”

“And then,” said Ram, “you can take hold of the backward-moving version of me and pull me—him—back into the normal timestream again.”

“Just what we need,” said Rigg. “More Ram Odins.”

“I’ve shepherded nineteen wallfolds for eleven thousand years,” said Ram. “What have you done?”

“You hurt his feelings,” said Noxon.

“He’s too sensitive,” said Rigg.