“No, sir. He would give no name. He simply said that you would quite understand, sir.”

Ronald Pryor did understand. Mark Marx was back again in England! It seemed incredible. But whose was that voice which in the night had warned him from Liverpool?

He ate his breakfast wondering. Should he tell Beryl? Should he reveal the whole curious truth to her? No. If he did so, she might become nervous and apprehensive. Why shake the nerves of a woman who did such fine work in the air? It would be best for him to keep his own counsel. Therefore, before he rose from the table, he had resolved to retain the secret of Marx’s return.

After breakfast Ronald, having taken from “The Hornet” the essential parts of his newly invented silencer, which, by the way, he daily expected would be adopted by the Government, carried them back to the house and there locked them in the big safe which he kept in his bedroom.

Then, later on, Beryl drove him to the station where he took train to London, and travelled down to his aeroplane factory, where, in secret, several big battleplanes of “The Hornet” type were being constructed.

It was a large, imposing place with many sheds and workshops, occupying a considerable area. The whole place was surrounded by a high wall, and, beyond, a barbed-wire entanglement, for the secrets of the work in progress were well guarded by trusty, armed watchmen night and day.

Pryor was seated in his office chatting with Mr. Woodhouse, the wide-awake and active manager, about certain business matters, when he suddenly said:

“By the way, it will be best to double all precautions against any information leaking out from here, and on no account to admit any strangers upon any pretext whatever. Even if any fresh Government viewer comes along he is not to enter until you have verified his identity-pass.”

“Very well,” was Woodhouse’s reply. “But why are we to be so very particular?”

“Well, I have my own reasons. Without doubt, our friend the enemy is extremely anxious to obtain the secrets of ‘The Hornet,’ and also the silencer. And in these days we must run no risks.”