Stone said, "If that's a meteor, it's damned funny-looking."

"What bothers you?"

"That left border, over there." Stone pointed to the screen. "The surface of the stone—if it is stone—is rough everywhere except on that left border, where it is smooth and rather straight."

"Like an artificial surface?"

Stone sighed. "If I keep looking at it," he said, "I might start to think so. Let's see those other patches of green."

Leavitt set the coordinates and focused the viewer. A new image appeared on the screens. This time, it was a close-up of one of the green patches. Under high magnification the borders could be seen clearly. They were not smooth, but slightly notched: they looked almost like a gear from the inside of a watch.

"I'll be damned," Leavitt said.

"It's not paint. That notching is too regular."

As they watched, it happened: the green spot turned purple for a fraction of a second, less than the blink of an eye. Then it turned green once more.

"Did you see that?"

"I saw it. You didn't change the lighting?"

"No. Didn't touch it."

A moment later, it happened again: green, a flash of purple, green again.

"Amazing."

"This may be—"

And then, as they watched, the spot turned purple and remained purple. The notches disappeared; the spot had enlarged slightly, filling in the V-shaped gaps. It was now a complete circle. It became green once more.

"It's growing," Stone said.

They worked swiftly. The movie cameras were brought down, recording from five angles at ninety-six frames per second. Another time-lapse camera clicked off frames at half-second intervals. Leavitt also brought down two more remote cameras, and set them at different angles from the original camera.

In main control, all three screens displayed different views of the green spot.

"Can we get more power? More magnification?" Stone said.

"No. You remember we decided 440 was the top."

Stone swore. To obtain higher magnification, they would have to go to a separate room, or else use the electron microscopes. In either case, it would take time.

Leavitt said, "Shall we start culture and isolation?"

"Yes. Might as well."

Leavitt turned the viewers back down to twenty power. They could now see that there were four areas of interest, three isolated green patches, and the rock with its indentation. On the control console, he pressed a button marked CULTURE, and a tray at the side of the room slid out, revealing stacks of circular, plastic-covered petri dishes. Inside each dish was a thin layer of growth medium.

The Wildfire project employed almost every known growth medium. The media were jellied compounds containing various nutrients on which bacteria would feed and multiply. Along with the usual laboratory standbys—horse and sheep blood agar, chocolate agar, simplex, Sabourad's medium—there were thirty diagnostic media, containing various sugars and minerals. Then there were forty-three specialized culture media, including those for growth of tubercule bacilli and unusual fungi, as well as the highly experimental media, designated by numbers: ME-997, ME-423, ME-A12, and so on.