The bolt he had withdrawn hung heavily in his jacket-pocket, and as he stood, alert and eager, there suddenly sounded the musical voice of a woman.

Next second he had slipped out of the hangar and gained cover in a thicket close by.

Beryl was crossing the grass, laughing gaily in the falling light. With her were Pryor, and Collins the mechanic. A few minutes before, Ronald and she, having finished dinner, had put on their flying-suits and, passing through the long windows out upon the lawn, had bidden farewell to Iris, as they were going on their usual patrol flight.

Ronald, leaving her suddenly, struck away to the hangar and, entering it, turned up the electric lights. With both hands he tested the steel stays of the great biplane, and then, aided by the mechanic, he wheeled the machine out ready for an ascent, for the atmospheric conditions were exactly suitable for an air raid by the enemy.

“We had better go up and test the engines, dear,” he suggested. “This afternoon they were not at all satisfactory.”

Beryl climbed into the observer’s seat, he following as pilot, while Collins disappeared round the corner of the hangar to get something.

Then the pair, seated beside each other and tightly strapped in, prepared to ascend in the increasing darkness.

The sudden roar of the powerful engines was terrific, and could be heard many miles away, for they were testing without the silencer.

Scarcely had they risen a hundred feet from the ground when there was a sharp crack and “The Hornet,” swerving, shed her right wing entirely, and dived straight with her nose to the earth.

A crash, a heavy thud, and in an instant Ronald and Beryl, happily strapped in their seats, were half-stunned by the concussion. Had they not been secured in their seats both must have been killed, as the man Leffner had intended.