[Illustration: A section of the cowling slid back. The helio slowed, hung suspended. Mary aimed slightly upward. She felt the automatic sight adjuster clicking delicately, the slight tug as the mags tilted the barrel directly into the meticulous balance of the firing jets.] As she fired, she sent the helio straight up at maximum speed and the cowling slid closed. * * * * * This was the end of her assignment. The gun's full charge had been exhausted. It was no longer of any use. She dropped it. She knew the hit had been direct. A glance showed the rocket already curving in a terrible kind of deceptive gentleness away to the right over New Washington. Soon its parabola would become a screaming plunge. Nothing could divert it. To try to destroy it in the air would mean nothing, for in any case, its deadly tons of G-Agent would be spread on the winds over the land. The Foundation and everything in it would by now be thoroughly contaminated by the G-Agent she had released inside. It would take a long time to decontaminate, to rebuild. And a lot of people were going to die, would be dying now. The antidote would save many from death. It would preserve others short of death in a state she could not envy, for to her it would be far worse than dying. But Mary could hardly concern herself with the wrecking of the Foundation, or the people who would die. Her concern was intense--to escape, to hide. And to know for certain whether or not, now that her task was done, the agonizing coercive directions from the Martian rocket would continue. So far there was no hint of this. She only wanted to get away. There were no invisible fingers probing in there, none of the drawing to tautness that had so many times ended in torture. Maybe, somehow, the directive rocket with its intricate mechanism was delicately equipped to know when her job was successfully done. She would soon know. The helio whined with strain. A shiver racked the metal. A scream burst from Mary's lips. She concentrated on her hands, forced the controls, drove the helio at maximum speed, trying to head across the park reserve toward the river and the great National Forest area. But already they were in close pursuit. Figures were running in all directions far below. The stars were breaking out and it was night now except for the glare of the exploding rocket far to the left. Now below the forest area shifted into view and the winding shine of the river. Night was the best time for the spreading of the G-Agent. Inversion was right. The stuff swept along close to the ground which cooled more slowly than the air. That, too, had been planned. The timing was right. Everything had been worked out right. But now--what was to happen to her? She felt none of the probing demands from the direction rocket. She felt not even a hint of them. Perhaps they had gone away forever and she was free. Free! FREE!