"But if they know about it," I objected, "how is it that McMurtrie and Savaroff aren't in Siberia? I've never heard that the Russians are particularly tender-hearted where traitors are concerned."

Latimer indulged in that peculiarly dry smile of his. "If the Government had got hold of them I think their destination would have been a much warmer one than Siberia. As it was they disappeared just in time. There was a gang of them--four or five at the least--and all men of position and influence. They must have made an enormous amount of money out of the j.a.ps. In the end one of them rounded on the others--at least that's what appears to have happened. Anyhow McMurtrie and Savaroff skipped, and skipped in such a hurry that they seem to have left most of their savings behind them. I suppose that's what made them start business again in England."

"You're absolutely sure they're the same pair?" asked Tommy.

"Absolutely. I've got their full description from the Russian police.

It tallies in every way--even to Savaroff's daughter. There _is_ a girl with them, I believe?"

"Yes," I said. "There's a girl." Then I paused for a moment. "Look here, Latimer," I went on. "What is it you want me to do? I'll help you in any way I can. When I made my bargain with McMurtrie I hadn't a notion what his real game was. I don't in the least want to buy my freedom by selling England to Germany. The only thing I flatly and utterly refuse to do is to serve out the rest of my sentence. If it's bound to come out who I am, you must give me your word I shall have a reasonable warning. I don't much mind dying--especially if I can arrange for ten minutes with George first--but quite candidly I'd see England wiped off the map before I'd go back to Dartmoor."

Latimer made a slight gesture with his hands. "You've saved my life, once at all events," he said. "It may seem a trifle to you, but it's a matter of quite considerable importance to me. I don't think you need worry about going back to Dartmoor--not as long as the Secret Service is in existence."

"Well, what is it you want me to do?" I asked again.

He was silent for a moment or two, as though arranging his ideas. Then he began to speak very slowly and deliberately.

"I want you to go on as if nothing had happened. Write to McMurtrie the first thing tomorrow morning and tell him that you've made the powder. He is sure to come down to the hut at once. You can show him that it's genuine, but on no account let him have any of it to take away. Tell him that you will only hand over the secret on receipt of a written agreement, and make him see that you're absolutely serious.

Meanwhile let me know everything that happens as soon as you possibly can. Telegraph to me at 145 Jermyn Street. You can send in the messages to Tilbury by the man who's looking after your boat. Use some quick simple cypher--suppose we say the alphabet backwards, Z for A and so on. Have you got plenty of money?"

I nodded. "I should like to have some sort of notion what you're going to do," I said. "It would be much more inspiriting than working in the dark."

"It depends entirely on the next two days. I shall go back to London tonight and find out if either of my men has got hold of any fresh information. Then I shall put the whole thing in front of Cas.e.m.e.nt. If he agrees with me I shall wait till the last possible moment before striking. We've enough evidence about the Devonport case to arrest McMurtrie and Savaroff straight away, but I feel it would be madness while there's a chance of getting to the bottom of this business.

Perhaps you understand now why I've risked everything tonight. We're playing for high stakes, Mr. Lyndon, and you--" he paused--"well, I'm inclined to think that you've the ace of trumps."

I stood up and faced him. "I hope so," I said. "I'm rather tired of being taken for the Knave."

"Isn't there a job for me?" asked Tommy pathetically. "I'm open for anything, especially if it wants a bit of physical violence."

"There will probably be a demand for that a little later on," said Latimer in his quiet drawl. "At present I want you to come back with me to London. I shall find plenty for you to do there, Morrison. The fewer people that are mixed up in this affair the better." He turned to me. "You can take the boat back to Tilbury alone if we go ash.o.r.e here?"

I nodded, and he once more held out his hand.

"We shall meet again soon," he said--"very soon I think. Have you ever read Longfellow?"

It was such a surprising question that I couldn't help smiling.

"Not recently," I said. "I haven't been in the mood for poetry the last two or three years."

He held my hand and his blue eyes looked steadily into mine.

"Ah," he said. "I don't want to be too optimistic, but there's a verse in Longfellow which I think you might like." He paused again. "It has something to do with the Mills of G.o.d," he added slowly.

CHAPTER XXI

SONIA'S SUDDEN VISIT

One's feelings are queer things. Personally I never have the least notion how a particular situation will affect me until I happen to find myself in it.

I should have thought, for instance, that Latimer's revelations would have left me in a state of vast excitement, but as a matter of fact I don't think I ever felt cooler in my life. I believe every other emotion was swallowed up in the relief of finding out something definite at last.

I know anyhow that that was my chief sensation as I rowed the dinghy towards the wet slimy causeway, lit by its solitary lamp. There was a boat train to town in the early hours of the morning which Latimer had suggested that he and Tommy should catch, and it certainly seemed a safer plan than coming back to Tilbury with me.

When I had parted from them, under the sleepy eye of a depressed-looking night watchman, I returned to the _Betty_ and proceeded to let go my moorings. I then ran up the sails, and gliding gently past the warships and a big incoming steamer, floated out into the broad peaceful darkness of the Thames estuary. I was in no hurry, and now that the mist had cleared away it was a perfect night for drifting comfortably up river with the tide.

The dawn was just beginning to break by the time I reached my old anchorage in the creek. In spite of my long and slightly strenuous day, I didn't feel particularly tired, so after stowing away the sails and tidying up things generally, I sat down in the cabin and began to compose my letter to McMurtrie.

I started off by telling him that I had completed my invention some days earlier than I expected to, and then gave him a brief but dramatic description of the success which had attended my first experiment. I am afraid I was a trifle inaccurate with regard to details, but the precise truth is a luxury that very few of us can afford to indulge in. I certainly couldn't. When I had finished I addressed the envelope to the Hotel Russell, and then, turning into one of the bunks, soon dropped off into a well-deserved sleep.

I don't know whether it was Nature that aroused me, or whether it was Mr. Gow. Anyway I woke up with the distinct impression that somebody was hailing the boat, and thrusting my head up through the hatch I discovered my faithful retainer standing on the bank.

He greeted me with a slightly apologetic air when I put off to fetch him.

"Good-mornin', sir. I hope I done right stoppin' ash.o.r.e, sir. The young lady told me I wouldn't be wanted not till this mornin'."

"The young lady was quite correct," I said. "You weren't." Then as we pushed off for the _Betty_ I added: "But I'm glad you've come back in good time today. I want you to go in and post a letter for me at Tilbury as soon as we've had some breakfast. You might get a newspaper for me at the same time."

"Talkin' o' noos, sir," observed Mr. Gow with sudden interest, "'ave you heard tell about the back o' Canvey Island bein' blown up yesterday mornin'?"

"Blown up!" I repeated as we ran alongside. "Who on earth did that?"

Mr. Gow shook his head as he clambered on board after me. "No one don't seem to know," he remarked. "'Twere done arly in the mornin', they reckon. There's some as says 'tis the suffrinjettes, but to my way o' thinkin' sir; it's more like to have somethin' to do with them blarsted Dutchmen as sunk my boat."

"By Jove!" I exclaimed, "I wonder if it had. They seem to be mischievous devils."

Mr. Gow nodded emphatically. "They are, sir, and that's a fact. 'Tis time somebody took a quiet look round that house o' theirs, some day when they ain't there."

How very nearly this desirable object had been achieved on the previous evening I thought it unnecessary to mention, but I was hugely relieved to learn that so far there was no suspicion as to who was really responsible for the damage to the creek. Apart from the inconvenience which it would have entailed, to be arrested for blowing up a bit of mud in a Thames backwater would have been a sad come-down for a convicted murderer!

As soon as he had provided me with some breakfast, Mr. Gow departed for Tilbury with my letter to McMurtrie in his pocket. He was away for a couple of hours, returning with a copy of the _Daily Mail_ and the information that there were no letters for me at the post-office.

I handed him over the _Betty_, with instructions not to desert her until he was relieved by either Tommy or Joyce or me, and then set off for the hut by my usual route. It was less than thirty hours since I had left it, but so many interesting things had happened in the interval it seemed more like three weeks.

For any one entangled in such a variety of perils as I appeared to be, I spent a surprisingly peaceful day. Not a soul came near the place, and except for reading the _Mail_ and indulging in a certain amount of hard thinking, I enjoyed the luxury of doing absolutely nothing. After the exertion and excitements of the previous twenty-four hours, this lull was exactly what I needed. It gave me time to take stock of my position in the light of Latimer's amazing revelations--a process which on the whole I found fairly satisfactory. If the likelihood of proving my innocence still seemed a trifle remote, I had at least penetrated some of the mystery which surrounded Dr. McMurtrie and his friends, and more and more it was becoming obvious to me that the two problems were closely connected. Anyhow I turned into bed in an optimistic mood, and with the stimulating feeling that in all probability I had a pleasantly eventful day in front of me.

It certainly opened in the most promising fashion. I woke up at eight, and was making a light breakfast off a tin of sardines and some incredibly stale bread, when through the little window that looked out towards the Tilbury road I suddenly spotted my youthful friend from the post-office approaching across the marsh. I opened the door, and he came up with a respectful grin of recognition.

"Letter for you, sir," he observed, "come this morning, sir."

He handed me an envelope addressed in Joyce's writing, and stood by while I read it, thoughtfully scratching his head with the peak of his cap. It was only a short note, but beautifully characteristic of Joyce.

"MY OWN NEIL,--

"I'm coming down to see you tomorrow afternoon. I've got several things to tell you, but the chief reason is because I want to kiss you and be kissed by you. Everything else seems rather unimportant compared with that.

"JOYCE."