"This little business has upset my plans, Luck," remarked Blake. "Or, rather, it will force my hand. It's no use trying to track the thieves. For one thing we have no clues; for another we simply haven't the time to waste. In the likely event of those plans reaching Germany, another month will result in the appearance of hostile battleplanes built to my specifications. So our task is to convince the War Office of the outstanding nature of my invention, and get the Royal Aircraft Factory people to set to work as hard as they can."
"You will have to make another set of working plans, I suppose?" remarked Dick.
"No, fortunately. As it happens I have both duplicate and triplicate tracings deposited at a London bank. However, that is not our immediate concern. What I propose doing is this. I'll motor into Church Stretton this morning and take old Harvey to the cottage hospital. Athol and you might make up arrears of sleep. This afternoon we'll tackle that little job you mentioned in connection with the dual drive. There are also a few adjustments necessary, which I noticed during our trial trip—not important, but certainly desirable. While I am in Church Stretton I'll engage a man and his wife as caretakers of the house while we're away. One never knows when we may be back. To-morrow at nine o'clock I intend starting on our flight to London."
Desmond Blake's plans worked smoothly. During the afternoon the suggested alterations to the driving transmission gear were satisfactorily carried out, and everything made ready for the momentous flight.
"I'm sending something of the nature of an ultimatum to the War Office," he remarked during the course of the evening. "You see we have to announce our arrival, otherwise the anti-aircraft guns might favour us with their unwelcome attentions. On the other hand it's worse than useless asking formal permission from the authorities to fly over the Metropolis. The application would drift to and fro between a dozen or more departments. Every little tinpot in office would have some remarks to make—I know them of old. The chances are that I would get an evasive reply in about a fortnight. Good heavens! If we had an Admiralty and a War Office purged of the somnolent civil element the war would be over by this time. So I've just cut in with a bald announcement. I've left a telegram to be dispatched at nine to-morrow—the time we start—stating that the Desmond Blake battleplane will manoeuvre over the Horse Guards Parade at 10 a.m. But we'll turn in now. It's getting late, and we've a full programme in front of us tomorrow."
"Do you mind if we sleep on board the battleplane?" asked Athol.
"Mind? No, of course not. But what's the object?"
"We've been talking it over," said Athol. "We thought that perhaps those spy Johnnies might pay us another visit."
"Hardly likely," replied Blake grimly. "They've collared the plans, and those will keep them quiet."
"I don't know so much about that," rejoined Dick. "They might think that that is our opinion, and consider it a favourable chance of returning and doing damage to the battleplane. That would give them a tremendous start."