It was exactly half-past ten on Tuesday morning when I sat down on the rough wooden bench in my workshop with a little gasp of relief and exhaustion. Before me, on the lead slab, was a small pile of dark brown powder, which an innocent stranger would in all probability have taken for finely ground coffee. It was not coffee, however; it was the fruit of four days and nights of about the most unremitting toil that any human being has ever accomplished. Unless I was wrong--utterly and hopelessly wrong--I had enough of the new explosive in front of me to blow this particular bit of marsh and salting into the middle of next week.

I leaned forward, and picking up a fistful, allowed it to trickle slowly through my fingers. The stuff was quite safe to handle; that was one of its beauties. I could have put a lighted match to it or thrown it on the fire without the faintest risk; the only possible method of releasing its appalling power being the explosion of a few grains of gunpowder or dynamite in its immediate vicinity. I had no intention of allowing that interesting event to occur until I had made certain necessary preparations.

I was still contemplating my handiwork with a sort of fatigued pride, when a sudden sound outside attracted my attention. Getting up and looking through the shed window, I discovered a telegraph-boy standing by the hut, apparently engaged in hunting for the bell.

"All right, sonny," I called out. "Bring it along here."

I walked to the door, and the next minute I was being handed an envelope addressed to me at the Tilbury Post-Office in Joyce's handwriting.

"It came the last post yesterday," explained the lad. "We couldn't let you have it until this morning because there wasn't any one to send."

"Well, sit down a moment, Charles," I said; "and I'll just see if there's any answer."

He seated himself on the bench, staring round at everything with obvious interest. With a pleasant feeling of antic.i.p.ation I slit open the envelope and pulled out its contents.

"CHELSEA,

"_Monday._

"DEAREST JAMES,

"It looks rather nice written--doesn't it! I am coming down tomorrow by the train which gets into Tilbury at 2.15. I shall walk across to the _Betty_ and sit there peacefully till you turn up. Whatever stage the work is at, don't be later than 7.30. I shall have supper ready by then--and it will be a supper worth eating. My poor darling, you must be simply starved. I've lots to tell you, James, but it will keep till tomorrow.

"With all my love,

"JOYCE."

I read this through (it was so like Joyce I could almost fancy I heard her speaking), and then I turned to the telegraph-boy, who was still occupied in taking stock of his surroundings.

"There's no answer, thank you, Charles," I said. "How much do I owe you?"

He pulled himself together abruptly. "It will be two shillings, the post-office fee, sir."

"Well, there it is," I said; "and there's another shilling for yourself."

He jumped up and pocketed the coins with an expression of grat.i.tude.

Then he paused irresolutely. "Beg pardon, sir," he observed, "but ain't you a gentleman who makes things?"

I laughed. "We most of us do that, Charles," I said, "if they're only mistakes."

He looked round the shed with an expression of slight awe. "Can you make fireworks?" he asked.

I glanced instinctively at the little heap of powder. "Of a kind," I admitted modestly. "Why?"

He gave an envious sigh. "I only wondered if it was hard, sir. I'd rather be able to make fireworks than do anything."

"It's not very hard," I said consolingly. "You go on bringing my letters and telegrams for me like a good boy directly they arrive, and before I leave here I'll show you how to do it. Only you mustn't talk about it to anybody, or I shall have everyone asking me the same thing."

His face brightened, and stammering out his thanks and his determination to keep the bargain a profound secret, he reluctantly took his departure. I felt that in future, whatever happened, I was pretty certain to get anything which turned up for me at the post-office without undue delay.

For the next half-hour or so I amused myself by constructing a kind of amateur magazine outside the hut in which to store my precious powder.

It was safe enough in a way above ground, as I have already mentioned, but with inquisitive strangers like Mr. Latimer prowling around, I certainly didn't mean to leave a grain of it about while I was absent from the shed. I packed it all away in a waterproof iron box, which I had specially ordered for the purpose, and buried it in the hole that I had dug outside. Then I covered the latter over with a couple of pieces of turf, and carefully removed all traces of my handiwork.

It was not until I had finished this little job that I suddenly realized how tired I was. For the last four days I had scarcely stirred outside the shed, and I don't suppose I had averaged more than three hours' sleep a night the whole time. The excitement and interest of my work had kept me going, and now that it was over I found that I was almost dropping with fatigue.

I locked up the place, and walking across to the hut, opened myself one of the bottles of champagne which I had so thoughtfully purchased at the Off-Licence. It was not exactly a vintage wine, but I was in no mood to be over-critical, and I drank off a couple of gla.s.ses with the utmost appreciation. Then I lay down on the bed, and in less than five minutes I was sleeping like a log.

I woke up at exactly half-past four. However tired I am, a few hours'

sleep always puts me right again, and by the time I had had a wash and changed into a clean shirt, I felt as fresh as a daisy.

I decided to walk straight over to the _Betty_. I knew that by this time Joyce would be on board, and as there was nothing else to be done in the shed, I thought I might just as well join her now as later. I had been too busy to miss any one very much the last four days, but now that the strain was over I felt curiously hungry to see her again.

Besides, I was longing to hear what news she had brought about Tommy and George.

With a view to contributing some modest item towards the supper programme, I shoved the other bottle of champagne into my pocket, and then lighting a cigar, locked up the place, and set off for the creek by my usual route. The tide was very high, and on several occasions I had to scramble up and make my way along the sea-wall in full view of the marsh and the roadway. Fortunately, however, there seemed, as usual, to be no one about, and I reached the mouth of the creek without much fear of having been watched or followed.

The _Betty_ was there all right, but I could see no sign of any one on board. I walked up the creek until I was exactly opposite where she was lying, and then putting my hands to my lips I gave her a gentle hail.

In an instant Joyce's head appeared out of the cabin, and the next moment she was on deck waving me a joyous welcome with the frying-pan.

"Oh, it's you!" she cried. "How lovely! Half a second, and I'll come over and fetch you."

"Where's Mr. Gow?" I called out.

"He's gone home. I sent him off for a holiday. There's no one on board but me."

She scrambled aft, and unshipping the dinghy, came sculling towards me across the intervening water. She was wearing a white jersey, and with her arms bare and her hair shining in the sunlight, she made a picture that only a blind man would have failed to find inspiring.

She brought up right against the bank where I was standing, and leaning over, caught hold of the gra.s.s.

"Jump," she said. "I'll hang on."

I jumped, and the next moment I was beside her in the boat, and we were hugging each other as cheerfully and naturally as two children.

"You dear, to come so soon!" she said. "I wasn't expecting you for ages."

I kissed her again, and then, picking up the oars, pushed off from the bank. "Joyce," I said, "I've done it! I've made enough of the blessed stuff to blow up half Tilbury."

She clapped her hands joyfully. "How splendid! I knew you would. Have you tried it?"

I shook my head. "Not yet," I said. "We'll do it early tomorrow morning, before any one's about." Then, digging in my scull to avoid a desolate-looking beacon, I added anxiously: "What about Tommy? Is he coming?"

Joyce nodded. "He'll be down tomorrow. I've got a letter for you from him. He saw Mr. Latimer last night."

"Did he!" said I. "Things are moving with a vengeance. What about the gentle George?"

Joyce laughed softly. "Oh," she said; "I've such lots to tell you, I hardly know where to start."