"Very good, sir. I'll send off a wireless when we are clear of this place. I'll land you on the Officers' Recreation Ground."
"That will do nicely," agreed Dacres as he took his seat.
Thirty-nine minutes after leaving Hyde Park the monoplane shaved past the tower of Portsmouth Town Hall and alighted at the spot the Irishman had suggested.
From a police inspector at the Dockyard gate Dacres elicited the information that Commander Hythe was engaged with the Commander-in-Chief, and that it was very doubtful whether he could be seen.
"But I must see him," declared Dacres peremptorily, "the Commander-in-Chief notwithstanding. This is official and not private business. Would you mind letting me have paper and envelope? I'll write a note and one of your men can take it to Commander Hythe."
Five minutes later a telephone message was received at the gate to the effect that Commander Hythe would receive Mr. Dacres at once.
"Hulloa, old man!" exclaimed the youthful commander as Dacres was shown into the office.
"You've come at a very busy time. I can give you five minutes only. What can I do for you?"
Hythe's usually cheerful face looked drawn and haggard. It seemed as if he had aged ten years since yesterday, when Dacres met him in Northumberland Avenue.
"I've been sent to warn you that the plans of the 'M' class of submarines are in danger."