know it.'
'I don't think I understand,' Pitt said. 'How does this help us?'
The smiles faded from Sheila's and Harlan's faces. They regarded each other for a beat, then retook their seats. Both were lost in thought.
'I'm not sure how this discovery is going to help us,' Sheila said finally. 'But it has to. I mean, it must be the alien Achilles' heel.'
'It must have been the way that they lulled off the dinosaurs,' Harlan said. 'Once they decided to end the infestation, the viruses all went from being latent to being virions. Then bam! They hit the oxygen and all hell broke loose.'
'That doesn't sound very scientific,' Sheila said with a smile.
Harlan laughed. 'I agree,' he said. 'But it gives us a hint. We have to induce the virus in the infected people to go from being latent to coming out of the cell.'
'How is a latent virus induced?' Pitt asked.
Harlan shrugged. 'A lot of ways,' he said. 'In tissue culture it's usually done with electromagnetic radiation like ultraviolet light or soft X rays like we used with the anaerobic bacterial culture.'
'There are some chemicals that can do it,' Sheila said.
'That's true,' Harlan. 'Some of the antimetabolites and other cellular poisons. But that doesn't help us. Neither do X rays. I mean it's not as if we could suddenly X-ray the planet.'
'Are there regular viruses that are latent like the alien virus?' Pitt asked.
'Plenty,' Sheila said.
'Absolutely,' Harlan agreed. 'Like the AIDS virus.'
'Or the whole herpes viral group,' Sheila said. 'They can hide out for life or cause intermittent problems.'
'You mean like cold sores?' Pitt asked.
'That's right,' Sheila said. 'That's herpes simplex. It stays latent in certain neurons.'
'So when you get a cold sore it means that a latent virus has been induced to form virus particles?' Pitt asked.
'That's right,' Sheila said with a touch of exasperation.
'I get cold sores every time I get a cold,' Pitt said. 'I suppose that's why they're called cold sores.'
'Very clever,' Sheila said sarcastically. 'Pitt, maybe you should leave us alone while we brainstorm. This isn't supposed to be a teaching session.'
'Wait a second,' Harlan said. 'Pitt just gave me an idea.'
'I did?' Pitt questioned innocently.
'You know what is the best viral induction agent?' Harlan asked rhetorically. 'Another viral infection.'
'How is that going to help us?' Sheila asked.
Harlan pointed to the large freezer door across the room. ''In there we've got all sorts of viruses. I'm starting to think that we should fight fire with fire!'
'You mean start some kind of epidemic?' Sheila asked.
'That's exactly what I'm thinking,' Harlan said. 'Something extraordinarily infectious.'
'But that freezer is full of viruses designed to be used as biological warfare agents. That will be like going from the frying pan into the fire.'
'Hell, that freezer has everything from nuisance viruses to the most deadly,' Harlan said. 'We just have to pick one that's suitable.'
'Well ... ' Sheila mused. 'It is true our original tissue culture was probably induced by the adenoviral vehicle we used for the DNA assay.'
'Come on!' Harlan said. 'Let me show you the inventory.'
Sheila stood up. She was very dubious about fighting fire with fire, but she wasn't about to dismiss the idea out of hand.
Next to the freezer was a desk with a bookshelf over it. On the bookshelf were three large, black looseleaf notebooks. Harlan handed one each to Sheila and Pitt. He cracked open the third himself.
'It's like a wine list at a fancy restaurant,' Harlan quipped. 'Remember, we need something infectious.'
'What do you mean, 'infectious'?' Pitt asked.
'Capable of being spread from person to person,' Harlan said. 'And we need the route to be airborne, not like AIDS or hepatitis. We want a worldwide epidemic.'
'God!' Pitt commented, looking at the index of his volume. ''I never thought there were so many different viruses. Here's filoviridae. Wow! There's Ebola in there.'
'Too virulent,' Harlan said. 'We want an illness that doesn't kill by itself so that an infected individual can spread it to as many others as possible. The rapidly fatal diseases, believe it or not, tend to be self-limiting.'
'Here's arenoviridae,' Sheila said.
'Still too virulent,' Harlan said.
'How about orthomyxoviridae?' Pitt said. 'Influenza is certainly infectious. And there's been some worldwide epidemics.'
'That has possibilities,' Harlan admitted. 'But it has a relatively long incubation period, and it can be fatal. I'd really like to find something rapidly infectious and a bit more benign. Here we go ... This is what I'm looking for.'
Harlan plopped the looseleaf he'd been holding onto the desktop. It was open to page 99. Sheila and Pitt bent over to look at it.
'Picomaviridae,' Pitt read, struggling with the pronunciation. 'What do they cause?'
'It's this genus that I'm interested in,' Harlan said. He pointed to one of the subgroups.
'Rhinovirus,' Pitt read.
'Exactly,' Harlan said. 'The common cold. Wouldn't it be ironic if the common cold were to save mankind?''
'But not everybody gets a cold when it goes around,' Pitt said.
'True,' Harlan said. 'Everyone has different levels of immunity to the hundreds of different strains that exist. But let's see what our microbiologists employed by the Pentagon have come up with.'
Harlan flipped through the pages until he came to the rhinovirus section. It comprised thirty-seven pages. The first page had an index of the serotypes plus a short summary section.
Everyone read the summary silently. It suggested that rhino viruses had limited utility as biological warfare agents. The reason given was that although the upper respiratory infections would affect the performance of a modern army, it would not be to a significant degree, and certainly not as much as an enterovirus causing diarrheal disease.
'Sounds like they were not so high on rhinoviruses,' Pitt said.
'True,' Harlan said. 'But we're not trying to incapacitate an army. We just want the virus to get in there and stir up metabolic trouble to bring the alien virus out in the open.'
'Here's something that sounds interesting,' Sheila said, pointing to a subsection in the index. It was artificial rhinoviruses.
'That's what we need,' Harlan said enthusiastically. He flipped through the pages until he came to the section. He read rapidly. Pitt tried to do the same, but the text might as well have been inscribed in Sanskrit. It was all highly technical jargon.
'This is perfect! Absolutely perfect!' Harlan said. He looked at Sheila. 'It's tailor-made, both literally and figuratively. They've put together a rhinovirus that has never seen the light of day, meaning no one has any immunity to it. It's a serotype that no one has ever been exposed to so everybody will catch it. It's ... made to order!'
''Seems to me we're making a rather large leap of faith here,' Sheila said. 'Don't you think we should somehow test this hypothesis?'
'Absolutely,' Harlan said with great excitement. He reached over and put his hand on the latch to the freezer door. 'I'll get a sample of the virus for us to grow out. Then we'll test it on those mice that I had infected. Boy, am I glad I did that.' Harlan opened the freezer and disappeared inside.
Pitt looked at Sheila. 'Do you think it will work?' he asked.
