It was a very cheerful little party dining that night at the Dormy House Club. There was Granet; Geoffrey Anselman, his cousin, who played for Cambridge and rowed two; Major Harrison, whose leave had been extended another three weeks; and the secretary of the club, who made up the quartette.

“By-the-bye, where were you this afternoon, Captain Granet?” the latter asked. “You left Anselman to play our best ball. Jolly good hiding he gave us, too.”

“Went out for a spin,” Granet explained, “and afterwards fell fast asleep in my room. Wonderful air, yours, you know,” he went on.

“I slept like a top last night,” Major Harrison declared. “The first three nights I was home I never closed my eyes.”

Granet leaned across the table to the secretary.

“Dickens,” he remarked, “that’s a queer-looking fellow at the further end of the room. Who is he?”

The secretary glanced around and smiled.

“You mean that little fellow with the glasses and the stoop? He arrived last night and asked for a match this morning. You see what a miserable wizened-up looking creature he is? I found him a twelve man and he wiped the floor with me. Guess what his handicap is?”

“No idea,” Granet replied. “Forty, I should think.”

“Scratch at St. Andrews,” Dickens told them. “His name’s Collins. I don’t’ know anything else about him. He’s paid for a week and we’re jolly glad to get visitors at all these times.”

“Bridge or billiards?” young Anselman asked, rising.

“Let’s play billiards,” Granet suggested. “The stretching across the table does me good.”

“We’ll have a snooker, then,” Major Harrison decided.

They played for some time. The wizened-looking little man came and watched them benevolently, peering every now and then through his spectacles, and applauding mildly any particularly good stroke. At eleven o’clock they turned out the lights and made their way to their rooms. Shortly before midnight, Granet, in his dressing-gown, stole softly across the passage and opened, without knocking, the door of a room opposite to him. The wizened-looking little man was seated upon the edge of the bed, half-dressed. Granet turned the key in the lock, stood for a moment listening and swung slowly around.

“Well?” he exclaimed softly.

The tenant of the room nodded. He had taken off his glasses and their absence revealed a face of strong individuality. He spoke quietly but distinctly.

“You have explored the house?”

“As far as I could,” Granet replied. “The place is almost in a state of siege.”

“Proves that we are on the right track, any way. What’s that building that seems to stand out in the water?”

“How do you know about it?” Granet demanded.

“I sailed out this evening, hired a boat at Brancaster Staithe. The fellow wouldn’t go anywhere near Market Burnham, though, and I’m rather sorry I tried to make him. They’ve got the scares here, right enough, Granet. I asked him to let me the boat for a week and he wasn’t even civil about it. Didn’t want no strangers around these shores, he told me. When I paid him for the afternoon he was surly about it and kept looking at my field-glasses.”

Granet frowned heavily.

“It isn’t going to be an easy matter,” he confessed. “I hear the Admiralty are going to take over the whole thing within the next few days, and are sending Marines down. How’s the time?”

They glanced at their watches. It was five minutes before midnight. As though by common consent, they both crossed to the window and stood looking out into the darkness. A slight wind was moving amongst the treetops, the night was clear but moonless. About half a mile away they could just discern a corner of the club-house. They stood watching it in silence. At five minutes past twelve, Granet shut his watch with a click.

“Not to-night, then,” he whispered. “Collins!”

“Well?”

“What is going on in that wooden shanty?”

The little man dropped his voice.

“Germany lost two submarines in one day,” he murmured. “The device which got them came from that little workshop of Worth’s. The plans are probably there or on the premises somewhere.”

Granet groaned.

“As a matter of fact I have been within a few yards of the thing,” he said. “It was all fenced around with match-boarding.”

“Do you mean that you have been allowed on board the Scorpion?”

Granet nodded.

“I had the rottenest luck,” he declared. “I took Miss Conyers and her friend down to see her brother, Commander Conyers. We were invited to lunch on board. At the last moment we were turned off. Through some glasses from the roof of the ‘Ship’ I saw some workmen pull down the match-boarding, but I couldn’t make out what the structure was.”

“I can give you an idea,” Collins remarked. “This fellow Worth has got hold of some system of concentric lenses, with extraordinary reflectors which enable him to see distinctly at least thirty feet under water. Then they have a recording instrument, according to which they alter the gradient of a new gun, with shells that explode under water. Von Lowitz was on the track of something of this sort last year, but he gave it up chiefly because Krupps wouldn’t guarantee him a shell.”

“Krupps gave it up a little too soon, then,” Granet muttered. “Collins, if we can’t smash up this little establishment there’ll be a dozen destroyers before long rigged up with this infernal contrivance.”

The little man stood before the window and gazed steadfastly out seawards.

“They’ll be here this week,” he said confidently. “You’d better go now, Granet. It’s all over for to-night.”

Granet nodded and left the room quietly. Every one in the Dormy House was sound asleep. He made his way back to his own apartment without difficulty. Only the little man remained seated at the window, with his eyes fixed upon the bank of murky clouds which lowered over the sea.