“The orbiter will obliterate all life within this wallfold.”

Umbo sighed. “I will not attempt to disable those procedures.”

Odinex said nothing.

“Turn and face me, Odinex,” said Umbo.

Odinex faced him.

“You killed me twice today.”

“I killed expendable copies of yourself,” said Odinex. “They came into existence because you jumped back in time, and by appearing in their presence, you changed their actions so when they reached the point in time when you time-shifted, they did not time-shift, and therefore they did not disappear.”

“How long might such duplicates continue to exist?” asked Umbo.

“Until they die.”

Umbo had never thought of this possibility. But it gave him a better understanding of how the duplicate ships had come into existence at the beginning of the human settlement of Garden.

“How did you kill them?” asked Umbo.

“I broke their necks and cast them off the bridge.”

“You are forbidden ever to destroy copies of me or any other time-shifter, without specific instructions to do so.”

“And which copy should I obey?” asked Odinex.

“The most recent one.”

“And how will I know which one that is?” asked Odinex.

“I’ll try to make sure it never comes up.”

“That would be best.”

“Odinex, show me everything on this ship that is not included in the plans that I studied in the library near the Wall.”

“The plans are complete.”

“No they’re not,” said Umbo. “They don’t show, for instance, where the spare copies of you are stored.”

“Intact copies of me are not stored anywhere. If this module fails, then a new one is assembled from the parts in parts storage, which is clearly labeled in the plans.”

“What triggers the creation of a new expendable?” asked Umbo.

“A death signal,” said Odinex. “A request for duplication. Loss of higher functions in the present module. Failure to communicate at any level for ten hours.”

“Who can issue the request for duplication?”

“The existing module. The certified commander of the vessel and all superior officers.”

“Thank you,” said Umbo. “Are the duplicates bound to obey all orders previously given to the earlier copy?”

“Yes,” said Odinex. “We are memory-identical.”

“Am I human, Odinex?”

“You are.”

“Is that what you’ll report to the Visitors when they arrive from Earth?”

“They will get a full memory dump of these events, along with all others,” said Odinex.

“They’ll see me make copies of myself by time-jumping?”

“Yes.”

Umbo wanted to grin, but restrained himself. Let the Visitors chew on that.

Then his pleasure faded. Seeing Umbo time-shift might well be a death sentence for Garden. To see someone suddenly pop into existence behind himself, and then again, so three copies exist at once—that wouldn’t exactly reassure the humans from Earth.

Well, it’s not as if they weren’t going to destroy Garden anyway. They’ve done it nine times already, and until now without any provocation from time-shifters.

It’s hard to imagine that I’ve somehow made the destruction of Garden worse. Will they say bad words while they wipe out all life on Garden? Will they throw stones at the corpses?

“Odinex, the jewels of control are not mentioned in the plans of the ship, or the computer manuals.”

The expendable said nothing.

“Consider that to be a question, and answer me,” said Umbo.

“The jewels are thoroughly explained in the plans and manuals.”

Umbo thought for a moment. “Under what name are they explained?”

“‘Remote storage and transfer of the ship’s log.’”

Umbo held up the knife and looked at the hilt. “These jewels are the log of each of the nineteen ships?”

“Yes.”

Remembering what he had read, Umbo said, “So each jewel contains a complete record of all actions and observations made by all the computers aboard that particular ship.”

“Yes.”

“Including all the actions of the Remote Expendable Action Modules.”

“Yes.”

“How recent is the information on each jewel?”

“The jewel that holds this starship’s log was updated just now when you certified.”

“And the other jewels?”

“The jewels carried by Rigg Sessamekesh were updated when he certified himself as commander of all the vessels.”

“And the jewels on this knife?”

“They were updated when you passed through the Wall.”

The Wall was certainly a lot more than a barrier between wallfolds. All human languages, and an update of all the ships’ logs. Umbo thought through what this might mean. “When a jewel updates, is it a destructive or a cumulative update?”

“Cumulative.”

“So if I were to time-shift and enter a Wall in an earlier time, the information recorded from the later time I came from would not be erased by the update that it subsequently gets in the earlier time.”

A momentary pause. “I have parsed your question and I can say, Yes, the information from a future time would not be erased by updating the ship’s log remote storage and transfer unit by passing into the Wall in an earlier era, as long as the time-shifter carried the log with him into the past.”

So the jewels would not suffer data loss by passing through the Wall and being updated in a back-shifted time. “If Rigg or I take a copy of the ships’ logs through the Wall when the Wall has been made passable according to Rigg’s command, is the log still updated?”

“Turning off the barrier features of the Wall does not turn off the Wall. All other functions continue.”

Umbo could not help himself. He laughed in delight.

“You are amused,” said the expendable.

I can be amused if I want and when I want, for whatever reason I want, Umbo wanted to say. Instead he grinned at the expendable. “The Odinfolders know this, don’t they?”

“Yes. I have kept no secrets from them.”

“Really?” said Umbo. “Have you told them about the deaths of all but one of the other Ram Odins?”

“I answer all their questions as fully as permitted.”

For a moment, Umbo took that as an answer to his question. Then he realized that it was not. “Has anyone ever asked that question?”

“You are the first.”

Umbo chuckled again. He not only knew information now that the Odinfolders had wanted to keep from him, he even knew information that they didn’t know. All in all, this was turning out to be a successful expedition.

“Odinex, please arrange for the ship to make me a good noon meal. Then bring it to me wherever I am in the ship.”

Odinex left the control room.

Umbo sat down in Ram Odin’s chair. This is where Rigg also sat in the ship in Vadeshfold. We’ve both sat in Ram Odin’s seat. Does that make us brothers in some sense?

I died twice today, he thought. He was glad that he had no memory of it. But the log had the memory of killing him. When the Visitors came, they would see it and know of all the murders committed by the expendables.

Maybe the destruction of Garden was as much to wipe out the expendables as to wipe out the people.

CHAPTER 15

Sibling Rivalry

Rigg had forgotten Umbo was gone, when Swims-in-the-Air came to him, looking agitated.

“I’m not sure what to make of this,” she said, “but our monitoring of the starship’s computer tells us that someone has activated the jewel of control and taken control of the ship.”

“Someone?” asked Rigg.

“Umbo,” said Swims-in-the-Air.

“Thank you for telling me.”

“What are you going to do?”

Rigg smiled at her. “Think about it for a while.”

“I’ve already summoned the flyer so you can go to the ship.”

“How thoughtful of you,” said Rigg. “I’ll decide whether to use it in a little while. Thank you. Please don’t bother the others with this story.”

“It’s not just a story,” she said, bristling.

“I should have said, Please don’t bother the others with this information.”