The Aztec began to tilt, falling off to the right.

He cast a quick glance at the engine instruments. A red light blinked. Number three was delivering slightly less thrust than the others. Somewhere in the complex of machinery a mechanical sensing device reacted. Engines one and two were throttled back and the rocket straightened. A second device shifted the mix on engine three, bringing thrust into balance. All three engines resumed full power.

"Twenty-five thousand feet," Prochaska chattered. His voice was tinny over the small insert earphone provided for communications, especially for those first few hellish moments when the whole universe seemed collapsed into one huge noise spectrum. Noise and pressure.

"Forty-five thousand...."

They were moving up fast now—three g, four g, five g. Crag's body weight was equal to 680 pounds. The dense reaches of the troposphere—the weather belt where storms are born—dropped below them. They hurtled through the rarefied, bitterly cold and utterly calm stratosphere.

"Eighty thousand feet...."

Crag struggled to move his body. His hand was leaden on the controls, as if all life had been choked from it. A hot metal ball filled his chest. He couldn't breathe. Panic ... until he remembered to breathe at the top of his lungs.

At eighteen miles a gale of wind drove west. Rudders on the Aztec compensated, she leaned slightly into the blast, negating its drift. The winds ceased ... rudders shifted ... the rocket slanted skyward. Faster ... faster.

Prochaska called off altitudes almost continuously, the chattering gone from his voice. Crag was still struggling against the pinning weight when it decreased, vanished. The firestream from the tail pipe gave a burst of smoke and died. Brennschluss—burnout.

The Aztec hurtled toward the cosmic-ray laden ionosphere, driven o