“Catch the what?” asked Ram.

“Click tones,” said Wheaton. “It’s a language, and it uses clicks.”

“It’s words,” corrected Noxon. “No syntax. All commands. Time for us to hide. They’re moving pretty fast.”

He had been thinking about what he was hearing and seeing and it was already too late to keep from being seen. The nearest wing man had spotted them and had veered toward them. Now he would see them disappear. Noxon wondered what he would think he saw—a shape like what he would think of as “people,” but mostly hairless, and wearing fabrics. And Deborah’s artificial eyes. Now you see us, now you don’t.

Except that the wing man kept heading right toward them, looking at them instead of looking back at the prey animal. Was he merely remembering where they had been?

No. Deborah was fumbling with her sound recorder. She was not holding Ram’s hand. She was not slicing with them. She was completely visible to the wing man.

And while Noxon was focused on Deborah, the wing man brought up an arm. Noxon finally saw it because the facemask saw it and forced his attention from Deborah to what the Erectid hunter was doing. He had a fist-sized stone in his hand and he was bringing back his arm and before Noxon could come out of sliced time to shout at Deborah the stone was already in the air, moving faster than any bird—though not so quickly that the facemask could not bring every moment of its flight to Noxon’s attention.

The trajectory was inevitable. It struck Deborah on the side of the head—she wasn’t looking at the wing man who threw at her—and dropped her instantly.

Noxon immediately stopped slicing time—he couldn’t stay invisible and bring her along with him. She would have to move to disappear that way. So now all three of the Sapient men were revealed to the wing man.

He didn’t even register surprise. He was already drawing another stone out of the bag tightly bound around his waist. Survival instinct—strange animals that looked like people, but not from his tribe. There was a constant state of war among Erectid tribes; if they ever had truces, Noxon had seen no evidence of it in their paths.

“Both of you hold on to me and Deborah,” said Noxon.

The wing man’s arm was going back for another throw.

Noxon jumped them all back to the future.

Wheaton was kneeling beside his daughter, checking her vital signs. He began to press on her chest, then breathe into her mouth.

“It’s no good,” said Noxon. “She’s dead.”

“People come back from heart stoppages,” said Wheaton as he pushed on her chest again.

“She’s dead,” said Noxon. “No path.”

After a half-minute this finally registered on Wheaton. He stopped trying to revive her. He just knelt there gasping.

“Calm down,” said Ram. “Remember what Noxon is. What he can do. She isn’t permanently dead. He can go back in time and prevent this.”

That was true, of course, and Noxon was already thinking about when he should intervene in the past in order to prevent it.

“Think of something,” said Wheaton. “Because I can’t bear to stay here much longer, looking down at her dead body.”

Noxon concentrated on Deborah’s corpse and pushed this lifeless object back about two hundred years.

Wheaton looked up in dismay. “What did you do!”

“What you asked me to do,” said Noxon.

“I know,” said Wheaton. “But now I know that there’s something worse than seeing her dead!”

“Quiet, quiet,” said Ram. “There are other people out here. In hovercars, yes, but they have mikes picking up sounds on the savannah.”

“How can you think about being quiet when . . .” But then Wheaton nodded. “I know. To you, she’s not really dead because she’s not going to stay dead. So let’s do it. Let’s go back and—”

“We can’t just go back,” said Noxon. “I mean, we can. But if the three of us appear to the four of us in the hotel, before we leave, it’ll change the paths of the past versions of ourselves, but as the agents of change we’ll still exist.”

“So there’ll be two copies of all of us,” said Ram.

“Except Deborah,” said Wheaton. “Worth it.”

“Seven of us to live on your already small income,” said Noxon.

“It’s Deborah’s life!” said Wheaton.

“I’m not proposing that we leave her dead,” said Noxon. “I’m just trying to think of a way to change the past without going there. So we don’t get copied.”

“Slice time and write a note,” said Ram. “You said you and your sister used to communicate that way.”

“If I’m there when the change happens, then whether it’s a note or a conversation, I’m still the agent of change, still present at the moment of change. I promise you, that’s how copying happens.”

“Then sneak in during the night and leave yourself a note that you’ll find in the morning,” said Wheaton.

“All right, yes,” said Noxon. “That’s good. But what should the note say? ‘Don’t go on the hunt’? ‘Make Deborah hold hands every second or she’ll be killed’?”

Ram asked Wheaton quite earnestly, “Would it work, just to warn her that not holding hands will result in her death? I mean, I’m sure she’d promise to comply, but in the moment, with that guy running at us with a stone in his hand—would she even think of her vulnerability?”

“I don’t know,” said Wheaton. “She thinks about whatever she’s thinking about, and not the things she’s not thinking about. She’s human.”

“So we forbid her to go?” asked Ram.

“Not sure she’d obey that,” said Noxon. “And if it isn’t her, it might be one of us.”

“We all held hands,” said Ram.

“But we were all distracted. Thinking and talking about language. He should never have seen us at all. I should have disappeared us much sooner. If I had done that, nothing would have gone wrong.”

“If if if,” said Wheaton.

“I’m a timeshaper,” said Noxon. “My life is all about ifs. When we make changes, it’s always in the belief that we understand what caused the problem and what the consequences of the changes we make will be. But nothing ever has just one cause, and nothing ever has just the predicted results.”

“So you fail all the time?” asked Wheaton.

“We mostly succeed,” said Noxon. “But the edges of everything we do are fuzzy. Nothing is really sharp and clear. So we spend a little time trying to think it through so we think of more choices and then choose the one we think is best.”

Ram and Wheaton fell silent then, for a few moments.

“If I were Umbo, I could just appear to myself in a vision,” said Noxon.

“You keep talking about the amazing powers of this mythical Umbo,” said Ram. “But he’s not here.”

“What I have to do is the equivalent of that. Like a vision. So yes, I think leaving a note is the best plan. But a long note. I’m going to lay out exactly what happened here and suggest ­several changes. I’ll tell us that their calls are language-like, and I’ll include the chip that has the recording. But then I’ll say, slice time from the moment you arrive there, and stay together.”

“Will that do it?” asked Ram.

“I don’t know,” said Noxon. “Because we don’t know what Erectids can see. It seemed to me that while he saw Deborah most clearly, because she wasn’t slicing time at all, he also saw us, or never lost track of where we were. I think I need to tell myself to slice time much more deeply, and trust the cameras to record everything. Which means we need to arrive much earlier and place cameras. I’ll tell us to do that.”

“We should have done that in the first place,” said Wheaton bitterly.

“What happens to us then, after you leave that note. Do we just . . . disappear?”

“I don’t know,” said Noxon.

“You said Umbo did this all the time,” said Ram.

“Yes, but you see, I’ve always been the guy who gets the warning,” said Noxon. “When we change our behavior, does that eliminate the timestream of the selves that sent the warning? Or merely diverge from it, leaving them to live with the bitter consequences of the mistakes they warned us not to make?”