Clark watched the scientists busy themselves for a long moment. They seemed so focused, so excited. A bunch of geeks playing games. None of them understood how this game was really played now.

"You know," he said, exhaling loudly once more, "this is just like those boring whatchamacallit things they did at NASA back in the sixties. The ones where they put those guys on roman candles and shot them into the sky. But not the sky sky. The dark stuff that's above the sky. Bo-ring." He made a few snoring noises. "Damned if I know how the old Canaveral guys drummed up any interest in that."

Engrossed in his work, Graham didn't bother to explain about the thrill of exploration that had driven everyone at NASA back in those heady days when all of space was new. Not that he had been around to see it. Pete Graham wasn't even born when man first walked on the moon.

His eyes sharp, Graham studied the movements of the probe he had built.

Popocatepetl was in one of its less active phases. Good thing, too. Virgil couldn't have survived inside an erupting volcano. But a completely dormant volcano was useless for their purposes. What they needed was a volcano with a recent active history that was in a down phase. With its constant threats of eruption, "Popo," as the Mexican volcano was commonly known, fit the bill perfectly.

A helicopter had lifted Virgil to the mouth of the volcano an hour ago. A thick cable from its belly had lowered the spiderlike device into the crater where ash and glowing red rocks lined the dark throat like a disease.

The trailer in which Pete Graham and his team monitored the progress of the probe was propped on rocks near a lava-and-mud-filled gorge beneath a freshly blown out parasitic cone. It was there they held their breath as they watched the probe being lowered into place.