“Hullo! Our anti-aircraft boys!” he ejaculated and at the same moment he pushed back the lever, causing the engines to roar again.

The men working the searchlight at once distinguished the tri-coloured rings upon the planes, and by its sudden silence and as sudden roar they knew it to be “The Hornet.” Therefore next second they shut off the beam of the light, and once again Ronnie silenced his ’bus.

It was then near midnight, and up there at ten thousand feet the wind was bitingly cold. Moreover there were one or two air currents which caused the machine to rock violently in a manner that would have alarmed any but those experienced in flying.

Beryl buttoned her collar still more snugly, but declared that she was not feeling cold. Below, little or nothing could be seen until, of a sudden, they ran into a thick cold mist, and then knew that they were over the sea.

With a glance at his luminous compass, the cheery young airman quickly turned the machine’s nose due south, and a quarter of an hour later altered his course south-west, heading towards London.

“Nothing doing to-night, it seems!” he remarked to his companion, as, in the darkness, they sped along at about fifty miles an hour, the wind whistling weirdly through the stays, the propeller humming musically, but the sound seeming no more than that of a bumblebee on a summer’s day.

It was certain that such sound could not be heard below.

After nearly an hour they realised by certain unmistakable signs—mostly atmospheric—that they were over the outer northern suburbs of London.

Then, as Ronnie altered his course, in the inky blackness of the night, both saw, deep below, an intense white light burning like a beacon, but throwing no ray.

“That’s curious!” remarked Pryor to the girl beside him. “I can’t make it out. I’ve seen it several times before. One night a month ago I saw it put out, and then, when one of our patrolling airships had gone over, it came suddenly up again.”