“Am I human?”
“Yes,” they both answered without hesitation.
“Who can change this definition?”
“You can,” said the ship and the expendable.
“Let one speak for both,” said Umbo.
The ship’s computer fell silent.
“You and Rigg Sessamekesh can change this definition,” said Odinex.
“Who else?”
“No one.”
Umbo knew this was not true, but also knew that the computers couldn’t lie.
“Is there a procedure by which someone else can gain the authority to change this definition without my or Rigg’s consent?”
“Yes.”
“Can you disable all procedures that would allow us to be superseded?”
“No.”
“Can I disable them?”
“Yes,” said the expendable.
In this situation, Umbo didn’t trust simple answers. “And if I do, what will be the consequences?”
“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.”