So he was there when they started talking about Simon’s illness. Simon was Peter’s father, a quiet man who was usually away, on expeditions with Peter’s mother, Ann. Now it appeared that he had something they called resistant leukemia. Vlad and Ursula noticed Nirgal listening, and they tried to reassure him, but Nirgal could see that they weren’t telling him everything. In fact they were regarding him with a strange speculative look. Later he climbed to his high room and got in bed and turned on his lectern, and looked up “Leukemia,” and read the abstract at the start of the entry. A potentially fatal disease, now usually amenable to treatment. Potentially fatal disease— a shocking concept. He tossed uneasily that night, plagued by dreams through the gray bird-chirp dawn. Plants died, animals died, but not people. But they were animals.

The next night he stayed up with the adults again, feeling exhausted and strange. Vlad and Ursula sat down on the floor beside him. They told him that Simon would be helped by a bone marrow transplant, and that he and Nirgal shared a rare type of blood. Neither Ann nor Peter had it, nor any of Nirgal’s brothers or sisters or halves. He had gotten it through his father, but even his father didn’t have it, not exactly. Just him and Simon, in all the sanctuaries. There were only five thousand people in all of the sanctuaries together, and Simon and Nirgal’s blood type was one in a million. Would he donate some of his bone marrow, they asked.

Hiroko was there in the commons, watching him. She rarely spent evenings in the village, and he didn’t need to look at her to know what she was thinking. They were made to give, she had always said, and this would be the ultimate gift. An act of pure viriditas. “Of course,” he said, happy at the opportunity.

• • •

The hospital was next to the bathhouse and the school. It was smaller than the school, and had five beds. They laid Simon on one, and Nirgal on another.

The old man smiled at him. He didn’t look sick, only old. Just like all the rest of the ancients, in fact. He had seldom said much, and now he said only, “Thanks, Nirgal.”

Nirgal nodded. Then to his surprise Simon went on: “I appreciate you doing this. The extraction will hurt afterward for a week or two, right down in the bone. That’s quite a thing to do for someone else.”

“But not if they really need it,” Nirgal said.

“Well, it’s a gift that I’ll try to repay, of course.”

Vlad and Ursula anesthetized Nirgal’s arm with a shot. “It isn’t really necessary to do both operations now, but it’s a good idea to have you two together for it. It will help the healing if you are friends.”