She chose not to answer his question. Instead, she said. “Sebastian is dead too, Rigo. Kinny lost one of her children. Persun Pollut was almost killed. His arm is terribly hurt. He may never carve again.” He was shamed into silence, and angered for being shamed. She walked toward the door, he following. “I’ve been working with Lees Bergrem,” she said, looking around to be sure she was not overheard “She thinks we’ve found a cure. She already had some of the pieces. It can’t be tested here on Grass. She’s sent word to Semling. They can manufacture the cure, get some victims together, and test it.”
“Manufacture?” he asked her, disbelieving. “Some kind of vaccine?” She nodded, coming close to him, actually hugging him, an awkward, one-armed embrace, tears on her face. “Not a vaccine at all. Oh, Rigo, I really think we’ve found the answer”
He reached for her, but she had already turned away. She would not say anything more until the people in Semling had received everything Lees Bergrem could send them. “Wait,” she said to Rigo and Roald and Kinny. “Don’t say anything to anyone until the word comes back. Don’t get people’s hopes up until we know for sure.”
Marjorie and Lees Bergrem spent the third day since their discovery fretting together, stalking back and forth through the echoing room where they had worked. On this day the Semling victims would either improve or go on dying. At noon on the fourth day the word came from Semling. Within hours of being treated, all the victims had started to mend.
“Now.” Marjorie was crying, tears flowing into the corners of her joyously curved mouth. “Now we can let everyone know.” She went to the tell-me to call Brother Mainoa. Only then did she learn he had died in the lap of a foxen, days before. Only then did she understand a part of what First had tried to tell her.
19
“Our job is over,” Marjorie said. “What we were sent to do is done.” She and Rigo and Father Sandoval were sitting at a table at Mayor Bee’s restaurant, drinking genuine Terran coffee. Around them the work of renewal went on. Renewal and burial. At the foot of the street, litter carriers went past, and Marjorie averted her eyes. She did not want to think any more about death.
“So you have said,” Father Sandoval said in the aloof voice he had used to her recently. “I’ve seen no proof of it.”
“I think I can explain it,” she offered. They had scarcely spoken during the past few days. Father Sandoval had not forgiven her for going off like that, though, since a cure had seemingly resulted, he had not said much about it. He had not forgiven Father James, either. He and Rigo had been discussing the recalcitrants, Rigo’s nephew, Rigo’s wife. Their emotions were at war with their sense of what was fitting, and she wanted to help them both. She said, “I can at least tell you what Lees Bergrem told me, what she’s telling everyone.”
Father Sandoval set his cup down and twisted it on the tabletop, leaving a wet circle there when he picked it up again. He touched the circle with a fingertip, stretching it, breaking it.
“Perhaps that would be useful,” he admitted.
She folded her hands in her lap, the way she had used to do as a child when called on to recite.
“Lees says that everything we’ve found in our universe has proven to share pretty much the same assortment of left-right molecules. She says there’s no particular reason that we know of why some molecules are twisted one way and some are twisted the other, but they are, everywhere we’ve been. Some of these substances are essential to different forms of life, and one of these is a nutrient, L-alanine. L-alanine exists everywhere we’ve ever been. Human cells, most cells, can’t get along without it.
“Here on Grass, however, a virus evolved which, as part of its process of reproduction, creates an enzyme, an isomerase, which converts L-alanine to D-alanine. L-alanine is the usual form. D-alanine is the mirror image, the isomer, and it is virtually nonexistent anywhere we know of. I’m quoting Lees exactly. She’s said it a hundred times, so I know I’ve got it right.” She stopped for a moment to drink, to watch Rigo watching her. He gestured vaguely, telling her to go on.
“After hundreds of thousands of years, the virus became widely dispersed here, in the living cells of all plants. As the plants died, the D form was released into the environment. Over time, here on Grass, the D form became as common as the L form. That’s the important fact, Rigo. Here on Grass, both D-alanine and L-alanine are floating around, ubiquitous. We can’t breathe or drink this coffee or eat anything grown here without taking in some of both — along with the virus.
“The minute we stepped off the ship from home, we were infected. The virus is in the air, in the dust, in the water. Lees says we probably had viruses in almost every cell of our bodies within minutes. The virus needs a co-factor in order to reproduce, however. A kind of activator. D-alanine is the co-factor. The viral protein binds to this co-factor, and then it converts L to D, very rapidly. However, the virus works both ways. It can also bind to L-alanine, and when it does, the viral protein converts D to L.
“Binding to D-alanine takes almost no time here on Grass because there’s so much D-alanine around. Someplace like Terra, where there are maybe only a few accidental molecules, it could take a long, long time. That’s why the plague was so slow to start elsewhere. It’s also why there isn’t any plague here on Grass. As soon as we started breathing on Grass, all our cells got supplied with D and L both.
“So, here on Grass, the virus inverts L, which we need in order to live, to D, which our bodies can’t use. However, since both D and L are plentiful, it turns both forms around simultaneously, and each of our cells finds enough L-alanine to go on living. On other planets there was little or no D-alanine to start with. When L was reversed, only D was left, and the cells couldn’t use it. When human cells died, the viruses escaped into neighboring cells in their immediately infective stage, and the process was repeated. People got sores that spread. Bandages, wash water, anything that touched the body served as a source of infection, and the dead cells provided the co-factor for newly infected cells.”
“But not here,” Rigo said stiffly.
“Not here. On Grass, both D-alanine and L-alanine are plentiful; our cells survive. The virus’s life cycle is interrupted, the cells die naturally. People come here and get infected and go away, never knowing it…”
“And it was spread by bats?” Father Sandoval asked.
“Lees says the bats don’t use alanine. It’s only one of a number of amino acids, and the bats just don’t use it. However, the blood of other animals has alanine in it. The bat doesn’t need it, so the viruses and the co-factors exist in the bat’s blood bladder. When bats die and dry, their insides are powdery with virus-rich material, as packed with viruses and with co-factors as a puffball is with spores. Dead blood-sucking bats are about as good a carrier as you could get.”
“You haven’t said what the cure is,” Father Sandoval said, finding on Rigo’s face an expression which reinforced his own mood, one of frustrated anger. One could not be angry that a cure had been found; one was, however, annoyed at the way it had been found.
“The cure?” She looked up, puzzled. “Well, of course, Father. I thought that was self-evident. All that’s needed is to spread massive quantities of D-alanine around. Small doses are no good. If somebody gets small doses of D, it will bind to the enzyme and they’ll die. But if they get massive amounts, more than is needed to bind, then there will be equal mixtures of L to D and D to L conversion And, of course, Semling found that it was extremely easy to make. They just used the virus to manufacture it out of L-alanine.”