He turned to the old man in yellow. “Put the aeropile upon the guides.”

The man in yellow hesitated.

“What do you mean to do?” cried Helen.

“This aeropile—it is a chance—.”

“You don’t mean—?”

“To fight—yes. To fight in the air. I have thought before—. An aeroplane is a clumsy thing. A resolute man—!”

“But—never since flying began—” cried the man in yellow.

“There has been no need. But now the time has come. Tell them now—send them my message—to put it upon the guides.”

The old man dumbly interrogated the man in yellow, nodded, and hurried out.

Helen made a step towards Graham. Her face was white. “But—How can one fight? You will be killed.”