ilent 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--damn '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 cou