Jeremy Stone, working with infinite patience, took a flake of the green material and dropped it into molten plastic. The plastic was the size and shape of a medicine capsule. He waited until the flake was firmly imbedded, and poured more plastic over it. He then transferred the plastic pill to the curing room.

Stone envied the others their mechanized routines. The preparation of samples for electron microscopy was still a delicate task requiring skilled human hands; the preparation of a good sample was as demanding a craft as that ever practiced by an artisan—and took almost as long to learn. Stone had worked for five years before he became proficient at it.

The plastic was cured in a special high-speed processing unit, but it would still take five hours to harden to proper consistency. The curing room would maintain a constant temperature of 61° C. with a relative humidity of 10 percent.

Once the plastic was hardened, he would scrape it away, and then flake off a small bit of green with a microtome. This would go into the electron microscope. The flake would have to be of the right thickness and size, a small round shaving 1,500 angstroms in depth, no more.

Only then could he look at the green stuff, whatever it was, at sixty thousand diameters magnification.

That, he thought, would be interesting.

In general, Stone believed the work was going well. They were making fine progress, moving forward in several promising lines of inquiry. But most important, they had time. There was no rush, no panic, no need to fear.

The bomb had been dropped on Piedmont. That would destroy airborne organisms, and neutralize the source of infection. Wildfire was the only place that any further infection could spread from, and Wildfire was specifically designed to prevent that. Should isolation be broken in the lab, the areas that were contaminated would automatically seal off. Within a half-second, sliding airtight doors would close, producing a new configuration for the lab.

This was necessary because past experience in other laboratories working in so-called axenic, or germ-free, atmospheres indicated that contamination occurred in 15 per cent of cases. The reasons were usually structural—a seal burst, a glove tore, a seam split—but the contamination occurred, nonetheless.

At Wildfire, they were prepared for that eventuality. But if it did not happen, and the odds were it would not, then they could work safely here for an indefinite period. They could spend a month, even a year, working on the organism. There was no problem, no problem at all.

Hall walked through the corridor, looking at the atomic-detonator substations. He was trying to memorize their positions. There were five on the floor, positioned at intervals along the central corridor. Each was the same: small silver boxes no larger than a cigarette packet. Each had a lock for the key, a green light that was burning, and a dark-red light.

Burton had explained the mechanism earlier. "There are sensors in all the duct systems and in all the labs. They monitor the air in the rooms by a variety of chemical, electronic, and straight bioassay devices. The bioassay is just a mouse whose heartbeat is being monitored. If anything goes wrong with the sensors, the lab automatically seals off. If the whole floor is contaminated, it will seal off, and the atomic device will cut in. When that happens, the green light will go out, and the red light will begin to blink. That signals the start of the three-minute interval. Unless you lock in your key, the bomb will go off at the end of three minutes."