"But you can't do that," Lynn pointed out shrewdly. "Factor Grossman said nothing about shooting me. He ordered that I was to be kept safely until he came."

"Yes," pondered the Titanian, "that is true. But I see no other way to—"

"I am afraid you will have to let me drive to Fort Beausejour. So long as I am driving, there is nothing you can do to prevent me taking the roller where I wish."

Grushl, who had been wrestling laboriously with the problem, now suddenly saw the light. His deepset eyes brightened. "Oh, no! There is another way!" he cried triumphantly. "I will drive the roller!"

"B-but—" cried Lynn.

"That is the solution. Stop the roller. You and I will change places. I will drive; you will move back here."

Obediently, Lynn drew the car to a halt, slipped from the driver's cubicle as the Titanian moved from the rear seat to take her place. Grushl smiled at her complacently. "You see?" he boasted. "It is really very simple. Now I can stop the roller wherever I wish. The Master will be obeyed." He reached for the controls laying his Haemholtz on the cushion beside him as he did so. That was what Lynn had been waiting for. In one sudden motion she leaned forward, scooped up the weapon.

"Sorry, Grushl!" she cried. "But it's you or me—"

She slashed the tube down hard upon the Titanian's scalp. Grushl groaned once, heavily—and sagged. His hands, falling away, dragged at the steering control-stick. In an instant the car jerked into convulsive motion, charged toward the edge of the road.

Lynn screamed and tugged at the door beside her. In a moment more she would have been carried out across the deadly sands without a shield of any sort. But just as the roller left the road, the girl threw herself through the door ... fell sprawling on the edge of the roadbed.