"And what have you guessed?"

"Oh, I won't trouble you with more guesses. I must find something out first--something really convincing, like that note book."

I was a little piqued, but I merely laughed and said,

"Well, we'll see!"

By this time we were quite near the house.

"Won't you come in and have lunch with us?" she asked.

The temptation was strong, but the scent seemed too warm to lose, and I said I must be back for lunch at home. We stopped, and as she looked at me I noticed in her eyes what first seemed to be doubt and anxiety and a moment later to become resolution.

"Mr. Merton," she said; her voice rather low, "which ever of us is right, I think we must be getting near rather a critical point. Don't you think you had better send off that wire to Captain Whiteclett?"

I shook my head.

"Not quite yet," I said. "You see it's a serious matter dragging my cousin out here unless one is quite certain he will be needed."

"But then he may not be in time!"

"I must risk that. But you may rest a.s.sured I'll wire the very instant I know it won't be bringing him out on a wild goose chase."

For an instant she was silent again, and then she suddenly said,

"I'm sure that writing was forged!"

It seemed to me that I read in her exclamation a kind of whipping up of her unbelief, as though she needed to rea.s.sure herself.

"A pair of gloves on it?" I suggested.

I quite confess that it was not one of my most tactful suggestions. She froze up again at once. Not that there was anything unkind in her eye as we said good-bye, only it was clear that in the meantime we were each going our own way.

I set out at my best pace back for I was hot for instant action, and Jean's doubts, though I dismissed them as quite unjustified by anything in the writing, nevertheless made me anxious to settle the question at once. The end might be very near indeed, I told myself, as I strode out with the last remains of my limp quite vanished. But what prompted those doubts; a genuine disbelief in the authenticity of the handwriting, or a perception of the logical consequences and a very natural shrinking from them? I wondered very much. The fact that she had refrained from asking a single question as to what I meant to do, suggested the second solution. And yet it was curiously unlike Jean Rendall's fearless spirit.

XV

PART OF THE TRUTH

I never remember feeling more intensely chagrined than when I reached our bleak house twenty minutes late for our early dinner to find the doctor had eaten a hurried meal quarter of an hour before the usual hour and rushed out to attend an urgent case.

I asked at once whether he had been told of the pocket book. Yes, it appeared he had. He had seemed very interested, but had immediately ordered his dinner hour to be advanced and then hurried away without putting further questions.

Was his haste a consequence of what he was told, or merely a coincidence? Well, I was resolved to leave that point in doubt no later than his return. I hardly debated at all the question of what to do. The baffling business of groping in the dark, and daily scheming to discover a window, without giving myself away, had gone on long enough. I had found a head at last and I meant to hit it. It might turn out to be the wrong head; still, I felt convinced I could scarcely fail to discover something fresh.

But though I proposed to take a bold course and make a short cut to the heart of this infernal mystery, I realised perfectly that if the cut actually led me there, it would prove an exceedingly dangerous by-way.

It was such a gamble that I shrank from summoning my cousin until it had come off, but I wrote out the code telegram we had arranged and put it in my pocket ready for emergencies. Of the doctor's two servants the younger anyhow was absolutely trustworthy I was convinced, and I meant to send her with the wire to the post office while I kept guard over the prisoner. And then, to ensure there being a prisoner, I saw that all the chambers of my revolver were loaded and put it in my coat pocket ready to my hand.

The afternoon dragged on, the wind still bl.u.s.tering round the house and the hail now and then rattling on the windows; but no Dr. Rendall appeared. Tea time arrived and still no sign of him. I gave him half an hour's grace and then had my own tea and returned to the smoking-room.

The evening by this time had fallen and the curtains were drawn and the lamps lit.

And then at last I heard him enter the front door. I jumped up and, with a dramatic instinct for taking the centre of the stage, placed myself before the fire, but I heard him run upstairs and it was some minutes before the sound of his descending steps reached me. The moment the door opened I was conscious that one of those peculiar changes I had so often noticed had taken place in the man. He smiled at me, but with a curiously furtive eye, and then he shut the door and came forward.

"You have had tea, I hope," said he.

I wasted no time in preliminaries. Keeping my right hand closed over the revolver in my pocket I held out the pocket book with my left.

"Dr. Rendall," I said, "you have heard that Bolton's pocket book has been found. Here it is. Kindly look at that entry."

The man started perceptibly and stared at me. Speaking in that tone and without my eye gla.s.ses I must have made an astonishing contrast to the Thomas Hobhouse he had last seen that morning at breakfast.

"Read that," I commanded.

He took the pocket book and I watched him closely. I saw his eyebrows rise as he read.

"What's all this about?" he asked.

"It is Bolton's last entry in his note book before he was murdered, and it means that O'Brien is either still in this island, or that a confederate of his is playing traitor in his place, and that one of the two has just committed murder. It is quite impossible that you don't know something of this!"

His blue eyes now had considerably more anger than guilt in them. In fact I was bound to admit that he looked a fine upstanding man, with his grey moustache, high colour, and an air of unmistakable indignation in his face.

"Who the devil are you?" he demanded.

"I may tell you that I am _not_ Thomas Sylvester Hobhouse, and that I have never taken liquor enough in my life to hurt myself. I am here to investigate certain things that have been going on in this island, and I'll put one question to you straight, Dr. Rendall. You remember being visited by a certain man Merton last August, When you heard him approaching your house why did you pull down your blind?"

That shot went straight home. All the indignation vanished and I saw on the instant I had him at my mercy.

"What--what--has that to do with it?" he stammered.

"Don't trouble to try and hedge. As a matter of fact I am Merton and I saw the blind go down myself. Since then we have always been on your tracks, Dr. Rendall."

"I swear that that had nothing to do with treason!"

"You are accused of treason, your relations to O'Brien were very peculiar, and if you can't explain that blind and this entry and a number of other things, you will be in an extremely nasty position."

The doctor made no further effort to stand up to me. He sank into a chair while I stood over him, and I knew I was going to hear the truth at last. And yet this sudden collapse, and indeed his whole att.i.tude, were so unexpected that I felt more puzzled than triumphant.

"Mr. Merton," he said, "for G.o.d's sake don't give me away and I'll tell you the whole truth. My cousin Philip can confirm it--or at least part of it. I came up here because--well, I'd married the wrong woman and gone off the rails a bit and Philip settled me here to keep me straight. I had debts too--I have them still, I may tell you frankly. That's why I took in O'Brien. I wasn't supposed to keep any liquor in the house--that was one of the conditions. But d.a.m.n it, I wasn't born to be a teetotaler, and that's the plain truth, Mr. Merton. That devil O'Brien found me out and started to blackmail me--"

"Blackmail?" I asked.

"In his own way. He made me give him liquor--and there we were the pair of us! That's why I pulled down the blind. The decanter and gla.s.ses were all out on this table here! And that's why O'Brien was afraid you might be sent by his relations. That was the one thing he was afraid of,--that he might be found out and taken away."

I bent over him and sniffed.