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 gratitude.  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 glasses 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.