“And was it?”

“Yes. But the weird part was how it was destroyed. The crew wasn’t allowed to just bag and dispose of it in the contaminated trash, which is what they’d normally do with a nonhazardous organism. No, Koenig told them to put the cultures in the hazardous waste disposal unit and incinerate them. And then to jettison the ash.”

Jack stopped on the path and stared at her. “If Dr. Koenig is a bioterrorist, why would she destroy her own weapon?”

“Your guess is as good as mine.” He thought about it for a moment, trying to make sense of it, but not coming up with an answer.

“Tell me more about her experiment,” he said. “What, exactly, is an Archaeon?”

“Petrovitch and I reviewed the scientific literature. Archaeons a bizarre domain of single-celled organisms called extremophiles—lovers of extreme conditions. They were discovered only twenty years ago, living—and thriving—near boiling volcanic vents on sea floor. They’ve also been found buried in polar ice caps and in rocks deep in the earth’s crust. Places we thought life couldn’t exist.”

“So they’re sort of like hardy bacteria?”

“No, they’re a completely separate branch of life. Literally, their name means the ancient ones. They’re so ancient, their origins date back to the universal ancestor of all life. A time before bacteria existed. Archaeons were some of the first inhabitants of our planet, and they’ll probably be the last to survive. No matter what happens—nuclear war, asteroid impact—they’ll be here, long after we’re extinct.” She paused. “In a sense, they’re earth’s ultimate conquerors.”

“Are they infectious?”

“No. They’re harmless to humans.”

“Then this isn’t our killer organism.”

“But what if something else was in that culture instead? What if she slipped in a different organism just before she shipped us payload? I find it interesting that Helen Koenig vanished just as this crisis was heating up.” Jack said nothing for a moment, his thoughts focused on why Helen Koenig would abruptly order her own experiment incinerated.

He remembered what Gordon Obie had said at their meeting.

Perhaps this was not an act of sabotage at all, but something just as frightening. A mistake.

“There’s more,” said Liz. “Something else about this experiment that raises the red flag for me.”

“What?”

“How it got funded. Experiments that come from outside NASA have to compete for room aboard the station. The scientist fills out the OLMSA application, explaining the possible commercial uses for the experiment. It gets reviewed by us and through various committees before we prioritize which ones get launched. The process takes a long time—at least a year or more.”

“How long did the Archaeon application take?”

“Six months.”

He frowned. “It was rushed through that quickly?”

Liz nodded. “Fast track. It didn’t have to compete for NASA funding, like most experiments do. It was a commercial reimbursable. Someone paid to send up that experiment.” That was, in fact, one of the ways NASA kept ISS financially viable—by selling payload space aboard the station to commercial users.

“So why would a company spend big bucks—and I do mean big bucks—to grow a test tube of essentially worthless organisms? Scientific curiosity?” She gave a skeptical snort. “I don’t think so.”

“Which company paid for it?”

“The firm Dr. Koenig worked for. SeaScience in La Jolla, California. They develop commercial products from the sea.” The despair Jack had felt earlier was finally lifting. Now he had information to work with. A plan of action. At last he could do something.

He said, “I need the address and phone number of SeaScience. And the name of that employee you spoke to.”

Liz gave a brisk nod. “You got it, Jack.”

August 17

Diana awakened from a restless sleep, her head aching, the dreams still clouding her mind. Dreams of England, of her childhood home in Cornwall.

Of the neat brick pathway leading to the front door, overhung by climbing roses. In her dream, she had pushed open the little gate and heard it squeal as it always did, the hinges in need of oil. She had started up the walkway to the stone cottage. Only a dozen paces and she would be on the front stoop, opening the door. Calling out that she was home, at last home. She wanted mother’s hugs, her mother’s forgiveness.

But the half dozen paces became a dozen. Two dozen. And still the cottage was out of reach, the pathway stretching longer and longer until the house had receded to the size of a doll’s.

Diana awakened with both arms reaching out, a cry of despair bursting from her throat.

She opened her eyes and saw Michael Griggs staring at her.

Though his face was partly obscured by a protective filter mask and goggles, she could see his expression of horror.

She unzipped her sleep restraint and floated across the Russian service module. Even before she looked in the mirror at her own reflection, she knew what she would see.

A flame of brilliant red was splashed across the white of her left eye.

Emma and Luther spoke in hushed voices as they floated together in the dimly lit hab. Most of the station was still in power down, only the Russian segment, which had its own self-contained electrical supply, was operating at full power. The U.S. end of station was reduced to an eerie maze of shadowy tunnels, and in gloom of the hab, the brightest source of light was the computer screen, on which the Environmental Control and Life Support System diagrams were currently displayed. Emma and Luther were already familiar with the ECLS system, had memorized its components and subsystems during their training on earth. Now they had an urgent reason to review the system. They had a contagion on board, and they could not be certain if the entire station was contaminated. When Nicolai had coughed, spraying eggs throughout the Russian service module, the hatch had been open.

Within seconds, the station’s air circulation system, designed to prevent pockets of dead air from building up, had swirled the airborne droplets into other parts of the station. Had the environmental-control system filtered out and trapped the airborne particles, as was designed to do? Or was the contagion everywhere now, in every module?

On the computer screen were diagrams of airflow into and out of the station’s atmosphere. Oxygen was supplied by several independent sources. The primary source was the Russian Elektron generator, which electrolyzed water into hydrogen and oxygen. A solid-fuel generator using chemical cartridges was one of the backup sources, as were the oxygen storage tanks, which were recharged by the shuttle. A plumbed system distributed the oxygen, mixed with nitrogen, throughout the station, and fans kept the air circulating between modules. Fans also drew in air through various scrubbers and filters, removing carbon dioxide, water, and airborne particles.

“These HEPA filters should’ve trapped every egg or larva within fifteen minutes,” said Luther, pointing to the high-efficiency particulate air filters in the diagram. “The system’s ninety-nine point nine percent efficient. Everything bigger than a third of a micron should’ve been filtered out.”

“Assuming the eggs stayed airborne,” said Emma. “The problem is, they adhere to surfaces. And I’ve seen them move. They could crawl into crevices, hide behind panels where we can’t see them.”

“It’d take months for us to rip out every panel and look for them. Even then, we’d probably miss a few.”

“Forget ripping out the panels. That’s hopeless. I’ll change out the rest of the HEPA filters. Recheck the microbial air samplers tomorrow. We have to assume that’ll do it. But if those larvae crawled into the electrical conduits, we’ll never find them.” She sighed, her fatigue so heavy she had to struggle to think.