By the time I had finished I was feeling distinctly hungry. I opened one of the tongues, and with the additional aid of bread and whisky made a simple but satisfying lunch. Then I sat down on the bed and treated myself to a pipe before going across to the shed to start work. Smoking in business hours is one of those agreeable luxuries which an inventor of high explosives finds it healthier to deny himself.

I could see no sign of any one about when I went outside. Except for a few gulls, which were wheeling backwards and forwards over the sea-wall, I seemed to have the whole stretch of marsh and saltings entirely to myself. Some people, I suppose, would have found the prospect a depressing one, but I was very far from sharing any such opinion. I like marsh scenery, and for the present at all events I was fully able to appreciate the charms which sages of all times are reported to have discovered in solitude.

I shall never forget the feeling of satisfaction with which I closed the door of the shed behind me and looked round its clean, well-lighted interior. A careful examination soon showed me that McMurtrie's share in the work had been done as thoroughly and conscientiously as I had imagined from my brief inspection on the previous day. Everything I had asked for was lying there in readiness, and, much as I disliked and mistrusted the doctor, it was not without a genuine sensation of grat.i.tude that I hung up my coat and proceeded to set to work.

Briefly speaking, my new discovery was an improvement on the famous C.

powder, invented by Lemartre. It was derived from the aromatic series of nitrates (which that great scientist always insisted to be the correct basis for stable and powerful explosives), but it owed its enormously increased force to a fresh const.i.tuent, the introduction of which was entirely my own idea. I had been working at it for about nine months before my arrest, and after several disappointing failures I had just succeeded in achieving what I believed to be my object, when my experiments had been so unkindly interrupted.

Still, all that remained now was comparatively clear sailing. I had merely to follow out my former process, and I had taken care to order the various ingredients in as fully prepared a state as possible for immediate use. I had also taken care to include one or two other articles, which as a matter of fact had nothing on earth to do with the business in hand. It was just as well, I felt, to obscure matters a trifle, in case any inquiring mind might attempt to investigate my secret.

For hour after hour I worked on, sorting out my various chemicals, and preparing such methods of treatment as were necessary in each case. I was so interested in my task that I paid no attention at all to the time, until with something of a shock I suddenly realized that the light was beginning to fail. Looking at my watch I found that it was nearly half-past seven.

There was still a certain amount to do before I could knock off, so, stopping for a moment to mix myself a well-earned whisky-and-water, I switched on the two electric head-lights which McMurtrie had provided as a means of illumination. With the aid of these I continued my labours for perhaps another hour and a half, at the end of which time I began to feel that a little rest and refreshment would be an agreeable variation in the programme.

After making sure that everything was safe, I turned out the lights, and locking up the door, walked back to the hut. I was just entering, when it suddenly struck me that instead of dining in solitary state off tongue and bread, I might just as well stroll over to the _Betty_ and take my evening repast in the engaging company of Mr. Gow.

No sooner had this excellent idea entered my head than I decided to put it into practice. The moon was out, and there appeared to be enough light to see my way by the old route along the river sh.o.r.e, so, walking down to the sea-wall, I climbed over, and set off in the direction of the creek.

It was tricky sort of work, with fine possibilities of spraining one's ankle about it, but by dint of "going delicately," like Agag, I managed to reach the end of my journey without disaster. As I rounded the bend I saw the _Betty_ lying out in mid-stream, bathed in a most becoming flood of moonlight. A closer observation showed me the head and shoulders of Mr. Gow protruding from the fo'c's'le hatch.

He responded to my hail by scrambling up on deck and lowering himself into the dinghy, which with a few vigorous jerks he brought to the sh.o.r.e.

"I've come to have supper with you, Mr. Gow," I observed. "Have you got anything to eat?"

He touched his cap and nodded. "I says to meself it must be you, sir, d'rectly I heard you comin' round the crick. There ain't much comp'ny 'bout here at night-time."

"Nor in the daytime either," I added, pushing the boat off from the bank.

"And that's a fact, sir," he remarked, settling down to the oars.

"There was one gent round here this morning askin' his way, but except for him we bin remarkable quiet."

"What sort of a gent?" I demanded with interest.

"Smallish, 'e was, sir, an' very civil spoken. Wanted to get to Tilbury."

"Did he ask who the boat belonged to, by any chance?"

Mr. Gow reflected for a moment. "Now you come to mention it, sir, I b'lieve 'e did. Not as I should have told 'im anything, even if I'd known. I don't hold with answerin' questions."

"You're quite right, Mr. Gow," I observed, catching hold of the stern of the _Betty_. "It's a habit that gets people into a lot of trouble--especially in the Law Courts."

We clambered on board, and while my companion made the dinghy fast, I went down into the cabin, and proceeded to rout out the lockers in search of provisions. I discovered a slab of pressed beef, and some rather stale bread and cheese, which I set out on the table, wondering to myself, as I did so, whether the inquisitive stranger of the morning was in any way connected with my affairs. It couldn't have been Latimer, for that gentleman was very far from being "smallish," a remark which applied equally well to our mutual friend with the scar.

I was still pondering over the question when I heard Mr. Gow drop down into the fo'c's'le, and summond him through the connecting door to come and join the feast.

He accepted my invitation with some embarra.s.sment, as became a "paid hand," but a bottle of Ba.s.s soon put him at his ease. We began by discussing various nautical topics, such as the relative merits of a centre-board or a keel for small boats, and whether whisky or beer was really the better drink when one was tired and wet through. It was not until we had finished our meal and were sitting outside enjoying our pipes that I broached the question that was at the back of my mind.

"Look here, Gow," I said abruptly, "were you speaking seriously when you suggested that launch ran you down on purpose?"

His face darkened, and then a curious look of slow cunning stole into it.

"Mebbe they did, and mebbe they didn't," he answered. "Anyway, I reckon they wouldn't have bin altogether sorry to see me at the bottom o' the river."

"But why?" I persisted. "What on earth have you been doing to them?"

Mr. Gow was silent for a moment. "'Tis like this, sir," he said at last. "Bein' about the river all times o' the day an' night, I see things as other people misses--things as per'aps it ain't too healthy to see."

"Well, what have you seen our pals doing?" I inquired.

"I don't say I seen 'em doin' nothin'--nothin' against the law, so to speak." He looked round cautiously. "All the same, sir," he added, lowering his voice, "it's my belief as they ain't livin' up there on Sheppey for no good purpose. Artists they calls 'emselves, but to my way o' thinking they're a sight more interested in forts an' ships an'

suchlike than they are in pickchers and paintin'."

I looked at him steadily for a moment. There was no doubt that the man was in earnest.

"You think they're spies?" I said quietly.

He nodded his head. "That's it, sir. Spies--that's what they are; a couple o' dirty Dutch spies--d.a.m.n 'em."

"Why don't you tell the police or the naval people?" I asked.

He laughed grimly. "They'd pay a lot of heed to the likes o' me, wouldn't they? You can lay them two fellers have got it all squared up fine and proper. Come to look into it, an' you'd find they was artists right enough; no, there wouldn't be no doubt about that. As like as not I'd get two years 'ard for perjurin' and blackmail."

To a certain extent I was in a position to sympathize with this point of view.

"Well, we must keep an eye on them ourselves," I said, "that's all.

We can't have German spies running up and down the Thames as if they owned the blessed place." I got up and knocked out my pipe. "The first thing to do," I added, "is to summons them for sinking your boat. If they _are_ spies, they'll pay up without a murmur, especially if they really tried to do it on purpose."

Mr. Gow nodded his head again, with a kind of vicious obstinacy. "They done it a-purpose all right," he repeated. "They seen me watching of 'em, and they knows that dead men tell no tales."

There scarcely seemed to me to be enough evidence for the certainty with which he cherished this opinion; but the mere possibility of its being a fact was sufficiently disturbing. Goodness knows, I didn't want to mix myself up in any further troubles, and yet, if these men were really German spies, and, in addition to that, sufficiently desperate to attempt a cold-blooded murder in order to cover up their traces, I had apparently let myself in for it with a vengeance.

Of course, if I liked, I could abandon Mr. Gow to pursue his claim without any a.s.sistance; but that was a solution which somehow or other failed to appeal to me. In a sense he had become my retainer; and we Lyndons are not given to deserting our retainers under any circ.u.mstances. At least, I shouldn't exactly have liked to face my father in another world with this particular weakness against my record.

Altogether it was in a far from serene state of mind that I climbed down into the dinghy, and allowed Mr. Gow to row me back to the bank.

"Will you be over tomorrow, sir?" he asked, as he stood up in the boat ready to push off.

"I don't think so, I shall be rather busy the next two or three days." Then I paused a moment. "Keep your eyes open generally, Mr.

Gow," I added; "and if any more gentlemen who have lost their way to Tilbury come and ask you the name of the _Betty's_ owner, tell them she belongs to the Bishop of London."

He touched his cap quite gravely. "Yessir," he said. "Good-night, sir."

"Good-night, Mr. Gow," I replied, and scrambling up the bank, I set off on my return journey.

CHAPTER XVIII

A NEW CLUE TO AN OLD CRIME