He knew his stay here was limited. He knew the toll now being exacted on his body, the steady seepage of calcium from his bones, the wasting of his muscles, the declining vigor of arteries and heart, now freed from the challenge of pumping against gravity. Every moment aboard ISS was precious, and he did not want to waste a minute of it. So, during the hours scheduled for sleep, he wfloated around the station, lingering at windows, visited the animals in the lab.
That was how he had discovered the dead mouse.
It had been floating with legs frozen and extended, pink mouth gaping open. Another one of the males. It was the fourth mouse to die in sixteen days.
He confirmed that the habitat was functioning properly, that the temperature set points had not been violated and the airflow rate was maintained at the standard twelve changes per hour. Why were they dying?
Could it be contamination of the water or food?
Several months ago, the station had lost a dozen rats when toxic chemicals had seeped into the animal habitat's water supply.
The mouse floated in a corner of the enclosure. The other males were bunched at the far end, as though repulsed by the corpse of their cage mate. They seemed frantic to get away from it, paws clinging to the cage screen. On the other side of the wire divider, the females, too, were bunched together. All except one. She was twitching, spiraling slowly in midair, her claws thrashing in seizurelike movements. Another one is sick.
Even as he watched, the female gave what looked like a last tortured gasp and suddenly went limp. The other females bunched even tighter, a panicked mass of writhing white fur. He had to remove the corpses, before the contagion -- if it was a contagion -- spread to the other mice.
He interfaced the habitat to the life-sciences glove box, snapped on latex gloves, and inserted his hands through the rubber dams. Reaching first into the male side of the enclosure, he removed the corpse and bagged it in plastic. Then he opened the females' enclosure and reached in for the second dead mouse. As he removed it, a flash of white fur shot out past his hand.
One of the mice had escaped into the glove box.
He snatched her in midair. And almost immediately released her when he felt the sharp nip of pain. She had bitten right through the glove.
At once he pulled his hands out of the box, quickly peeled off the gloves, and stared at his finger. A drop of blood welled up, the sight of it so unexpected, he felt nauseated. He closed his eyes, berating himself. This was nothing -- barely a prick. The mouse's rightful vengeance for all those needles he had stuck in it. He opened his eyes again, but the nausea was still there.
I need to rest, he thought.
He recaptured the struggling mouse and thrust it into the cage. Then he removed the two bagged corpses and placed them in the refrigerator. Tomorrow, he'd deal with the problem. Tomorrow, when he felt better.
July 30.
'I found this one dead today,' said Kenichi. 'It is number six.'
Emma frowned at the mice in the animal habitat. They were housed in a divided cage, the males separated from the females only by a wire barrier. They shared the same air, the same food water supply. On the male side, a dead mouse floated motionless, limbs extended and rigid.
The other males were clustered at the opposite end of the enclosure, scrabbling at the screen as though frantic to escape.
'You've lost six mice in seventeen days?' said Emma.
'Five males. One female.' Emma studied the remaining live animals for signs of illness.
They all appeared alert, their eyes bright, with no mucus from their nostrils.
'First, let's get this dead one out,' she said. 'Then we'll take a close look at the others.' Using the glove box, she reached into the cage and removed the corpse. It was already in rigor mortis, the legs stiff, the body inflexible. The mouth was partly open, and the tip of the tongue protruded in a soft flap of pink. It was not unusual for lab mice to die in space. On one shuttle flight in 1998, there had been a hundred percent mortality among newborn rats. Microgravity was an alien environment, and not all species adapted well.
Prior to launch, these mice would have been screened for a number of bacteria, fungi, and viruses. If this was an infection, then they had picked it up while aboard ISS. She put the dead mouse in a plastic pouch, changed gloves, and reached into the enclosure for one of the live mice. It squirmed with great vigor, showing no signs of illness. The only unusual thing was a tattered ear that had been chewed by its cage mates. She flipped over to look at its belly and gave an exclamation of surprise.
'This is a female,' she said.
'What?'
'You had a female in the male enclosure.' Kenichi leaned close to peer through the glove box window at the mouse's genitals. The evidence was plain to see. His face flushed deep red with embarrassment.
'Last night,' he explained. 'She bit me. I put her back in a hurry.'
Emma gave him a sympathetic smile. 'Well, the worst that can happen is an unexpected baby boom.' Kenichi slipped on gloves and inserted his hands in the second pair of glove box armholes. 'I make the mistake,' he said. 'I fix it.' Together they examined the rest of the mice in the enclosure, but found no other misplaced specimens. All appeared healthy.
'This is very strange,' said Emma. 'If we're dealing with a contagious disease, there ought to be some evidence of infection.'
'Watson?' a voice called over the module intercom.
'In the lab, Griggs,' she answered.
'You've got priority E-mail from Payloads.'
'I'll get it now.' She sealed off the animal enclosure and said to Kenichi, 'Let me check my message. Why don't you take out the dead mice you put in cold storage. We'll look at them.' He nodded and floated across to the refrigerator.
At the workstation computer, she called up her priority Email. To, Dr. Emma WatsonFrom, Helen Koenig, Principal InvestigatorRe, Experiment CCU#Z3 [Archaeon Cell Culture] Message, Immediately abort this experiment. Latest specimens returned by Atlantis show fungal contamination. All Archaeon cultures, along with the containers holding them, should be incinerated in onboard crucible and the ashes jettisoned.
Emma read and reread the message on the screen. Never before had she received such a strange request. Fungal contamination was not dangerous.
To incinerate the cultures seemed a drastic overreaction. She was so preoccupied by this puzzling request she paid no attention to Kenichi, who was taking the dead mice out of the refrigerator. Only when she heard him gasp did she turn to look at him.
At first all she saw was his shocked face, splattered with a foul slurry of entrails. Then she looked at the plastic bag that had burst open. In his horror, he had released it, and it floated free, hanging in the air between them.
'What is that?' she said.
He said, in disbelief, 'The mouse.' But it was not a dead mouse she saw in the bag. It was a mass of disintegrated tissue, a putrefied gumbo of flesh and fur that now was leaking out foul-smelling globules.
Biohazard!
She shot the length of the module to the caution-and-warning panel and hit the button to shut off airflow between modules.
Kenichi had already opened the emergency rack and pulled out two filter masks. He tossed one to her, and she clapped it over her own mouth. They didn't need to exchange a word, they both knew what had to be done.
Quickly they closed the hatches on either end of the module, effectively isolating the lab from the rest of the station. Then took out a biocontainment bag and carefully moved toward the drifting bag of liquefied flesh. Surface tension had bound the droplets together in one globule, if she was careful not to stir the air, she could trap it in the
