I ran the boat alongside the _Betty_, and we both climbed on board.

"Suppose we start by having some tea," I suggested. "I'm dying for a cup."

"You poor dear," said Joyce. "Of course you shall have one. You can read what Tommy says while I'm getting it ready."

She fetched the letter out of the cabin, and sitting in the well I proceeded to decipher the three foolscap pages of hieroglyphics which Tommy is pleased to describe as his handwriting. As far as I could make out they ran as follows:

"MY DEAR NEIL,

"I suppose I oughtn't to begin like that, in case somebody else got hold of the letter. It doesn't matter really, however, because Joyce is bringing it down, and you can tear the d.a.m.n thing up as soon as you've read it.

"Well, I've seen Latimer. I wrote to him directly I got back, reminded him who I was, and told him I wanted to have a chat with him about some very special private business. He asked me to come round to his rooms in Jermyn Street last night at ten o'clock, and I was there till pretty near midnight.

"I thought I was bound to find out something, but good Lord, Neil, it came off in a way I'd never dared hope for. Practically speaking, I've got to the bottom of the whole business--at least so far as Latimer's concerned. You see he either had to explain or else tell me to go to the devil, and as he thought I was a perfectly safe sort of chap to be honest with, he decided to make a clean breast of it.

"To start with, it's very much what we suspected. Latimer _is_ a Secret Service man, and that's how he comes to be mixed up in the job.

It seems that some little while ago the Admiralty or one of the other Government departments got it into their heads that there were a number of Germans over in England spying out the land in view of a possible row over this Servian business. Latimer was told off amongst others to look into the matter. He had been sniffing around for some weeks without much luck, when more or less by chance he dropped across the track of those two very identical beauties who ran down Gow's boat in the Thames last Friday.

"Somehow or other they must have got wind of the fact that he was after them, and they evidently made up their minds to get rid of him.

They seem to have set about it rather neatly. The man with the scar, who is either one of them or else in with them, introduced himself to Latimer as a member of the French Secret Service. He pretended that he had some special information about the case in hand, and although Latimer was a bit suspicious, he agreed to dine at Parelli's and hear what the fellow had to say.

"Well, you know the rest of that little incident. If it hadn't been for you there's not the faintest doubt that Latimer would have copped it all right, and I can tell you he's by way of being rather particularly grateful. I was specially instructed to send you a message to that effect next time I was writing.

"What the connection is between your crowd and these Germans I can't exactly make out. Of course if you're right in your idea about the chap with the scar spying on you in London it's perfectly obvious they're working together in some way. At the same time I'm quite sure that Latimer knows nothing about it. The reason he came down to look at the hut on Friday was because a report about it had been sent to him by one of his men--he has two fellows working under him--and he thought it might have something to do with the Germans. He described the way you had caught him quite frankly, and told me how he'd had to invent a lie about the Surveyor in order to get out of it.

"Exactly what he means to do next I don't know. He has got some plan on, and I've a notion he wants me to help him--at least he sounded me pretty plainly last night as to whether I'd be game to lend him a hand. I need hardly tell you I jumped at the idea. It seems to me our only possible chance of finding out anything. I am to see him or hear from him tomorrow, and directly I know what's in the wind I'll either write to you or come and look you up.

"Joyce will tell you all about George and McMurtrie. If they aren't both up to some kind of particularly dirty mischief I'll eat my whole wardrobe. We must talk it over thoroughly when we meet.

"I'm longing to see you again, and hear all about the work and what's been going on down there.

"So long, old son,

"Yours as ever,

"TOMMY."

I was just making out the last words, when Joyce emerged from the cabin, carrying some tea on a tray.

"Here you are, Neil," she said. "I have cut you only two slices of bread and b.u.t.ter, because I don't want you to spoil your supper.

There's cold pheasant and peas and new potatoes."

I pulled out the bottle of champagne from my pocket. "If they're as new as this wine," I observed, "they ought to be delicious."

Joyce accepted my contribution, and after reading the label, placed it carefully on the floor of the well. "Sarcon et fils," she repeated. "I always thought they made vinegar."

"Perhaps they do," I replied. "We shall know when we drink it."

Joyce laughed, and sitting down beside me, poured me out a cup of tea.

"You've read Tommy's letter," she said. "What do you think about it?"

I took a long drink. "From the little I've seen of Mr. Bruce Latimer,"

I said, "I should put him down as being one of the most accomplished liars in England." I paused. "At the same time," I added, "I think he's a fine fellow. I like his face."

Joyce nodded her head. "But you don't believe his story?"

I shrugged my shoulders. "It may be true," I said. "Tommy seems to think so anyhow. If it is, things are a bit simpler than I imagined--that's all."

"And if it isn't?" said Joyce.

"Ah!" said I, "if it isn't--"

I left the sentence unfinished, and helped myself to a second bit of bread and b.u.t.ter.

There was a short silence.

"Tell me about George, Joyce," I went on. "What are these particular dark doings that Tommy's hinting about?"

Joyce leaned forward with her chin on her hands, her blue eyes fixed on mine.

"Neil," she said slowly, "I've found out something at last--something I thought I was never going to. I know who the man was in Marks's rooms on the day that he was murdered."

I was so surprised that I gulped down a mouthful of nearly boiling tea.

"I wish you'd break these things more gently, Joyce," I said. "Who was it?"

"It was Dr. McMurtrie."

I put down the teacup and stared at her in the blankest amazement.

"Dr. McMurtrie!" I repeated incredulously.

She nodded. "Listen, and I'll tell you exactly how it all happened. I dined with George, as you know, at the Savoy on Friday, and we went into the whole business of my going away with him. He has got that twelve thousand pounds, Neil; there's no doubt about it. He showed me the entry in his pa.s.s-book and the acknowledgment from the bank, and he even offered to write me a cheque for a couple of hundred right away, to buy clothes with for the trip."

"From what I remember of George," I said, "he must be desperately in love with you."

Joyce gave a little shiver of disgust. "Of course I let him think I was giving way. I wanted to find out where the money had come from, but try as I would, I couldn't get him to tell me. That makes me feel so certain there's something wrong about it. In the end I arranged to dine with him again tomorrow night, when I said I'd give him my final answer. On Sat.u.r.day morning, however, I changed my mind, and wrote him a note to say I'd come Thursday instead. I didn't mean to tie myself to be back tomorrow, in case you wanted me here."

She paused.

"I had to go up Victoria Street, so I thought I'd leave the letter at his office. I'd just got there, and I was standing outside the door opening my bag, when a man came down the steps. I looked up as he pa.s.sed, and--oh Neil!--it was all I could do to stop myself from screaming. I knew him at once; I knew his cold wicked face just as well as if it had been only three days instead of three years. It was the man I'd seen in Marks's rooms on the afternoon of the murder."

She stopped again, and took a deep breath.

"I was horribly excited, and yet at the same time I felt quite cool. I let him get about ten yards away down the street, and then I started off after him. He walked as far as the Stores. Then he called an empty taxi that was coming past, and I heard him tell the driver to go to the Hotel Russell. I thought about how you'd followed the man with the scar, and I made up my mind I'd do the same thing. I had to wait for several seconds before another taxi came by, but directly it did I jumped in and told the man to drive me to the corner of Russell Square.

"I got there just as the other taxi was drawing up in front of the hotel. A porter came forward and opened the door, and I saw the man get out and go up the steps. I waited for one moment, and then I walked along to the entrance myself. The porter was still standing there, so I went straight up to him and asked him quite simply what the name of the gentleman was who had just gone inside. He sort of hesitated, and then he said to me: 'That gentleman, Miss?--that's Dr.

McMurtrie.'"