Citadel, and we now came to the long, low building of Dartmoor stone, which is the Plymouth Headquarters of the A.P. It is perched on the edge of the cliff, and within five yards of the spot where Sir Francis Drake is said to have finished his game of bowls when the Armada was coming up Channel.

We passed through the gates, where the police sentry presented arms, and began to walk up and down the terrace.

"Signal to Southampton," I ordered, "and get a couple of their fastest boats here at once. They may be useful in an emergency, and it will look as if we are doing something. Ready for action, of course, and with full service ammunition and bombs. Sir Joshua may have a fit if he likes, but there is nothing to be done until we know more—unless you can suggest anything?"

The little man shook his head. He was keen as a terrier, of course, and he had already acted with great promptitude and wisdom.

Just then an orderly came out on to the terrace and handed me a signal.

I read it out to Lashmar: "Air-yacht May Flower just passed St. Mary's doing ninety knots." It was from our most westerly A.P. station on Tresco in the Scillies. Lashmar made a rough calculation: "Twenty-five miles west-sou'-west of Land's End, add another seventy—she'll be here just under the hour, sir."

"Then I tell you what, Mr. Lashmar, go and meet her and escort her home. Not a living soul must speak to Captain Pring before I do—not even Sir Joshua or any of the White Star people. Give that as my orders when you meet the yacht. But put it very politely to Mr. Van Adams—my compliments and that sort of thing. He's the sort of person who could buy the goodwill of the universe for ready money. Make your escort appear a compliment from the Government!"

Lashmar never wasted words. He understood exactly, saluted, and hurried to the electric railway, which ran down like a chute into the sea-drome far below. I lit a cigarette and watched, and it was a sight worth watching.

Beyond, stretched the largest sea-drome in Great Britain, a harbour within a harbour, surrounded by massive concrete walls. In the roughest weather, when even within the distant breakwater the Sound is turbulent, the sea-drome is calm as a duck-pond. Now it was like a sheet of polished silver, and resting on their great floats at their moorings were three gigantic air-liners, with electric launches and motor-boats plying between them and the landing-stages.

Right in the centre was the splendid Atlantis, graceful as a swan, by which Connie was to leave for the States in a few hours. She was surrounded by a swarm of boats no bigger than water-beetles from where I stood.

A bell rang, there was a rumbling sound, and from a tunnel just beneath me the car, with Lashmar in it, shot down to the water like a stone running down a house roof. As the car dwindled to a punt, a match-box, and finally a postage stamp, I heard the creak and swish of the semaphore behind me on the roof of the station. On the far side of the sea-drome was our Patrol Ship No. 1, stream-line fusilage, with the familiar red, white and blue line, snow-white planes, guns fore and aft, and twin propellers of phosphor bronze winking white-hot in the afternoon sun.

The semaphore was sighted in five seconds. I got a pair of glasses, and saw that the engines were already "ticking over" as Lashmar jumped into a launch and went over the pool, with a cream-white wake behind him and two ostrich plumes of spray six feet high at the bows. He was on board in less time than it takes to write it. I heard the faint throbbing of the four high-compression engines change to the drone of a hornet. No. 1 Patrol slid over the water until her floats lifted—lifted until they barely touched the surface, and she was clear. One clean spiral over Pinklecombe way, and then, as she mounted, she turned and was off over Rams Head like an arrow from a bow. Though I say it that shouldn't, my officers and men of the A.P. were just about as good as they're made!

There was a good three-quarters of an hour to spare, and the Royal Hotel was not four minutes away. After the recent excitements a cup of tea with Connie seemed just the thing. As I legged it over the Hoe, I realized that I might be very busy for some time, and, in consequence, late for dinner. I must tell my girl that something of great importance had happened, though, in any case, I was determined to see her off, come what might.

Then I remembered something. As Chief Commissioner I had absolute control over the airports of England in a time of crisis. In any case, it would be as well to, close the sea-drome in preparation for the May Flower's arrival. I should then be certain that no one could possibly get at Captain Pring before I could. And if I chose to detain even the Royal Mail for half an hour later on in the evening—under the circumstances!—no one would say me nay.

There is a telephone box in the hall of the Royal Hotel. In thirty seconds my orders were given, and not a living soul would enter or leave Plymouth sea-drome without my permission. Then I strolled into the winter gardens, where I found Connie sitting at a little table among tubs of azaleas and listening to the strains of a ladies' orchestra.

"I've half an hour and ten minutes exactly, darling," I said, putting my watch on the table and helping her to early strawberries. "Tell me when the time's up, and then I must rush away for an hour before we dine."

Straightway I forgot all about the Albatros, Captain Pring, and the mysterious armed ship in mid-Atlantic.

Knowing what I know now, I wonder how I could have taken it so lightly, even then. But grave and serious as the affair was, amazing, too, in its boldness, an elaborate and unexpected masterpiece of crime, it seemed remote and very far away, like something one reads of in a foreign newspaper, never conceiving that it can have anything to do with one's own personal life.

If only I could have peeped but a little way into the future!

CHAPTER III "COLD-BLOODED PIRACY IN THE HIGH AIR"

Pilot-commander Pring was a tall, lean, lantern-jawed officer, who, though of English nationality, had spent most of his life in America. His face was still pale and grim with passion and mortification as I closed the door of my private room at the A.P. Station on him, Mr. Van Adams, the multi-millionaire, and Mr. Rickaby, second officer of the Albatros.

"Now, gentlemen, sit down, please," I said. "And I will ask Captain Pring a few questions. Sir Joshua Johnson has given me the main facts, but I want details. I won't detain you long, but I felt I ought to see you before anyone else."

"Oh, quite!" said Mr. Van Adams, a fleshy man, with a watchful eye and a jaw like a pike.

"This is an extraordinary affair, Captain Pring," I went on. "But, thank goodness, you haven't lost your ship, or any lives. I know what you feel about the Albatros."

"She is father, mother, brother, sister, hired girl and dog under the waggon to me!" said Pring, and then he blazed up into fury. I disentangle the few words I can. The majority were too overdressed for respectable society.

"... His Majesty's Mails! First time in history of flying, and it's happened to ME! Cold-blooded piracy in the High Air! They'd have blown us to pieces as soon as look at us! When I get hold of that slime-lapping leper, the pirate skipper, I won't leave him hide or hair to cover the wart he calls