Visitors (Pathfinder 3)

“Ignore the mice,” said the expendable. “They have nothing like your ability. It merely amuses them to snipe at you.”

“I know,” said Noxon. But Father’s reassurance made him feel better. That hadn’t changed, although he knew “Father” was a machine.

“Have you looked for the outbound path?” asked Ram Odin.

“I don’t have to look for paths,” said Noxon. “They’re just there.”

“But this one isn’t. So now you do have to look for it. And that may be why you haven’t seen it, because you aren’t used to having to look for paths.”

“I have to search out individuals among the mesh of intersecting paths,” said Noxon. “But they’re always visible. Or present, anyway.”

“I get it that you don’t see them with your eyes,” said Ram. “But since we don’t have words for the ability to sense people’s passages through time and space, just use the words for vision.”

“All right, yes, of course,” said Noxon. That’s what he and Umbo had always done.

“So what I’m thinking is, you won’t see a path, because causality is going the other direction,” said Ram.

“That’s what I’m thinking, too,” said Noxon. “But that would imply that we’re doomed.”

“It’s not all I was thinking, if you want to hear the rest,” said Ram Odin.

“Oh, we do, we do!” cried the mice in their chirpy sarcastic voices.

“People moving through time the same direction as you, they make a path the way movies do it—one instant hasn’t faded out before the next one begins.”

“Because instants don’t exist,” said Noxon.

“Well, they do,” said the expendable. “You just can’t distinguish them.”

“Continuity, that’s my point,” said Ram. “But when they’re running backward, you don’t get any continuity at all. Still, that doesn’t mean you can’t see each—forgive me, each instant—but only for an instant.”

“I don’t see any,” said Noxon.

“You haven’t looked,” said Ram. “You’ve looked for continuous paths. But what happened when Umbo slowed you down in time? Your perception of paths changed. They started individuating. You could see that they were people. You could see faces. The slower you went, the more clearly you saw them.”

“Because the whole continuity was there,” said Noxon. “No matter how slow I go, they still connect, they still make a continuous movement.”

“Exactly my point,” said Ram. “Maybe the most you can sense of backward paths is momentary slices. No continuity.”

“How can I see those? They don’t exist long enough to be seen.”

“You don’t know that,” said Ram, “because you haven’t looked.”

Noxon shook his head. “How can I slow myself down enough to sense something whose existence in our timeflow has no duration?”

Ram shrugged. “Got any better ideas?”

“The ship has been calculating,” said the expendable, “and your physics is correct. Each instant of the backward path would have no duration. Except that this is also true of forward paths, and you see those.”

“Because of causal continuity,” said Noxon.

“That’s your guess,” said the expendable. “It’s a good guess, unless it’s wrong. But I think you’re probably right. That doesn’t change anything. The other timeflow also has causal continuity. So what’s to say there isn’t a lingering image? Not an after-image, as with ordinary timeflow, but a pre-image, a semi-physical memory of what is about to happen, because in that timeflow, it already happened. Each instant caused the next and the next. Maybe there’s enough of causality clinging to each instant of a human life that it becomes visible.”

“If that were true,” said Noxon, “I should see them already.”

“No,” said the expendable. “Because they’re unhappening. Causality is unraveling, in the direction we’re going. Each instant is unmade as you sense it. So instead of a path, a continuity of events, it’s a series of discontinuities. An unpath.”

“Clever naming,” said Noxon. “But you don’t know what you’re talking about.”