“I think he’s having a squint round,” said Tommy.  “Anyhow I know he’s there on his own and depending on me to pick him up.”

“But what made him ask you?” I demanded.

“He knew I had a boat, and I fancy he’s working this particular racket without any official help.  As far as I can make out, he wants to be quite certain what these fellows are up to before he strikes.  You don’t get much sympathy in the Secret Service if you happen to make a mistake.”

“Well, it’s no good wasting time talking,” I said.  “If we want to be there by half-past nine we must push off at once.”

“But what about you?” exclaimed Tommy.  “You can’t come!  He’s seen you, you know, at the hut.”

“What does it matter?” I objected.  “If he didn’t recognize me as the chap who sent him the note at Parelli’s, we can easily fake up some explanation.  Tell him I’m a new member of the Athenians, and that you happened to run across me and brought me down to help work the boat.  There’s no reason one shouldn’t be a yachtsman and a photographer too.”

I spoke lightly, but as a matter of fact I was some way from trusting Tommy’s judgment implicitly with regard to Latimer’s straightforwardness about the restaurant incident, and also about his visit to the hut.  All the same, I was quite determined to go to Sheppey.  Things had come to a point now when there was nothing to be gained by over-caution.  Either Latimer had recognized me or else he hadn’t.  In the first event, he knew already that Tommy had been trying to deceive him, and that the mythical artist person was none other than myself.  If that were so, I felt it was best to take the bull by the horns, and try to find out exactly what part he suspected me of playing.  I had at least saved his life, and although we live in an ungrateful world, he seemed bound to be more or less prejudiced in my favour.

Apart from these considerations, Tommy would certainly want some help in working the Betty.  He knew his job well enough, but with a haze on the river and the twilight drawing in rapidly, the mouth of the Thames is no place for single-handed sailing—­especially when you’re in a hurry.

Tommy evidently recognized this, for he raised no further objections.

“Very well,” he said, with a rather reckless laugh.  “We’re gambling a bit, but that’s the fault of the cards.  Up with the anchor, Neil, and let’s get a move on her.”

I hauled in the chain, and then jumped up to attend to the sails, which I had just let down loosely on deck, in my hurry to put off in the dinghy.  After a couple of unsuccessful efforts and two or three very successful oaths, Tommy persuaded the engine to start, and we throbbed off slowly down the creek—­now quite a respectable estuary of tidal water.

I sat back in the well with a laugh.  “I never expected a second trip tonight,” I said.  “I’m beginning to feel rather like the captain of a penny steamer.”