But as he flew along he almost hoped that he was in for action. For that was the way with Bill Barlow. Fellow war aces had said that he “fattened on trouble.”

And, if that was the case, there was enough trouble ahead to make Bill Barlow very fat indeed.

III

Bill flew straight north for awhile and had no difficulty picking up the Trinidad road which wound about the foothills rimming Pampa to the north. After he had skimmed over the hills he swung lower in order to scout the highway thoroughly.

He passed over a couple of little settlements and climbed to a higher altitude, for there was mountainous country ahead. It was after he had climbed high and had sailed over the summit that he made out a low-flying plane ahead.

He used his binoculars—the plane was the green De Haviland of the night before, as he had suspected it would be. But the hawk would wait for its prey in vain if Saxton’s telephone call had been in time. And then, as he zoomed along, he saw that he was in for action.

A turreted car of the type used by banks to transport money and bullion swept around a hairpin turn in the road that hugged a steep bluff, and as soon as the car had swung into the straight road Bill saw a grayish cloud shoot up just ahead of the car. It looked to him as if a bomb had been dropped; and yet it did not seem possible from the position of the green plane.

Bill Barlow put on all speed, and tilted his aërilons to climb. He was planning to get above the green plane and keep it below and in front of him where he would be safe from that machine gun nested in front of the pilot.

In this manner he might be able to take the joy-stick between his knees, get a pot-shot at the pilot, and send the green ship down out of control. It was a long chance, but it was his only one, and Bill Barlow had fought against long odds before.

He hardly believed he was seen as yet, and he nosed up steadily toward a low-hanging cloud. And then, as he climbed, he noticed, backgrounded against the cloud, another plane—a big blue-gray one, that seemed almost to blend into the cloud. This, then, was probably the explanation of that explosion that had taken place in front of the armored car.