Not often in a life-time does a man stand on the edge of eternity, but when I spoke those words in that East End cellar I was perfectly certain that they were my last words on earth. I braced myself for the shock of those black, rushing waters beneath, and experienced in advance the horror of that breath-choking fall.

But to my surprise a low laugh fell on my ears. I opened my eyes. Obeying a sign from the man on the divan, my two jailers brought me back to my old seat facing him.

"You are a brave man, Captain Hastings," he said. "We of the East appreciate bravery. I may say that I expected you to act as you have done. That brings us to the appointed second act of our little drama. Death for yourself you have faced—will you face death for another?"

"What do you mean?" I asked hoarsely, a horrible fear creeping over me.

"Surely you have not forgotten the lady who is in our power—the Rose of the Garden."

I stared at him in dumb agony.

"I think, Captain Hastings, that you will write that letter. See, I have a cable form here. The message I shall write on it depends on you, and means life or death for your wife."

The sweat broke out on my brow. My tormentor continued, smiling amiably, and speaking with perfect sangfroid:—

"There, captain, the pen is ready to your hand. You have only to write. If not—"

"If not?" I echoed.

"If not, that lady that you love dies—and dies slowly. My master, Li Chang Yen, amuses himself in his spare hours by devising new and ingenious methods of tortures—"

"My God!" I cried. "You fiend! Not that—you wouldn't do that—"

"Shall I recount to you some of his devices?"

Without heeding my cry of protest, his speech flowed on—evenly, serenely—till with a cry of horror I clapped my hands to my ears.

"It is enough, I see. Take up the pen and write."

"You would not dare—"

"Your speech is foolishness, and you know it. Take up the pen and write."

"If I do?"

"Your wife goes free. The cable shall be despatched immediately."

"How do I know that you will keep faith with me?"

"I swear it to you on the sacred tombs of my ancestors. Moreover, judge for yourself—why should I wish to do her harm? Her detention will have answered its purpose."

"And—and Poirot?"

"We will keep him in safe custody until we have concluded our operations. Then we will let him go."

"Will you swear that also on the tombs of your ancestors?"

"I have sworn one oath to you. That should be sufficient."

My heart sank. I was betraying my friend—to what? For a moment I hesitated—then the terrible alternative rose like a nightmare before my eyes. Cinderella—in the hands of these Chinese devils, dying by slow torture—

A groan rose to my lips. I seized the pen. Perhaps by careful wording of the letter, I could convey a warning, and Poirot would be enabled to avoid the trap. It was the only hope.

But even that hope was not to remain. The Chinaman's voice rose, suave and courteous.

"Permit me to dictate to you."

He paused, consulted a sheaf of notes that lay by his side, and then dictated as follows:—

"Dear Poirot, I think I'm on the track of Number Four. A Chinaman came this afternoon and lured me down here with a bogus message. Luckily I saw through his little game in time, and gave him the slip. Then I turned the tables on him, and managed to do a bit of shadowing on my own account—rather neatly too, I flatter myself. I'm getting a bright young lad to carry this to you. Give him a half a crown, will you? That's what I promised him if it was delivered safely. I'm watching the house, and daren't leave. I shall wait for you until six o'clock, and if you haven't come then, I'll have a try at getting into the house on my own. It's too good a chance to miss, and, of course, the boy mightn't find you. But if he does, get him to bring you down here right away. And cover up those precious moustaches of yours in case any one's watching out from the house and might recognise you.

"Yours in haste,

"A. H."

Every word that I wrote plunged me deeper in despair. The thing was diabolically clever. I realised how closely every detail of our life must be known. It was just such an epistle as I might have penned myself. The acknowledgment that the Chinaman who had called that afternoon had endeavoured to "lure me away" discounted any good I might have done by leaving my "sign" of four books. It had been a trap, and I had seen through it, that was what Poirot would think. The time, too, was cleverly planned. Poirot, on receiving the note, would have just time to rush off with his innocent-looking guide, and that he would do so, I knew. My determination to make my way into the house would bring him post haste. He always displayed a ridiculous distrust of my capacities. He would be convinced that I was running into danger without being equal to the situation, and would rush down to take command of the situation.

But there was nothing to be done. I wrote as bidden. My captor took the note from me, read it, then nodded his head approvingly and handed it to one of the silent attendants who disappeared with it behind one of the silken hangings on the wall which masked a doorway.

With a smile the man opposite to me picked up a cable form and wrote. He handed it to me.

It read: "Release the white bird with all despatch."

I gave a sigh of relief.

"You will send it at once?" I urged.

He smiled, and shook his head.

"When M. Hercule Poirot is in my hands it shall be sent. Not until then."

"But you promised—"

"If this device fails, I may have need of our white bird—to persuade you to further efforts."

I grew white with anger.

"My God! If you—"

He waved a long slim yellow hand.

"Be reassured, I do not think it will fail. And the moment M. Poirot is in our hands, I will keep my oath."

"If you play me false."

"I have sworn it by my honoured ancestors. Have no fear. Rest here awhile. My servants will see to your needs whilst I am absent."

I was left alone in this strange underground nest of luxury. The second Chinese attendant had reappeared. One of them brought food and drink and offered it to me, but I waved them aside. I was sick—sick—at heart—

And then suddenly the master reappeared tall and stately in his silken robes. He directed operations. By his orders I was hustled back through the cellar and tunnel into the original house I had entered. There they took me into a ground floor room. The windows were shuttered, but one could see through the cracks into the street. An old ragged man was shuffling along the opposite side of the road, and when I saw him make a sign to the window, I understood that he was one of the gang on watch.

"It is well," said my Chinese friend. "Hercule Poirot has fallen into the trap. He approaches now—and alone except for the boy who guides him. Now, Captain Hastings, you have still one more part to play. Unless you show yourself he will not enter the house. When he arrives opposite, you must go out on the step and beckon him in."

"What?" I cried, revolted.

"You play that part alone. Remember the price of failure. If Hercule Poirot suspects anything is amiss and does not enter the house, your wife dies by the Seventy lingering Deaths! Ah! Here he is."

With a beating heart, and a feeling of deathly sickness, I looked through the crack in the shutters. In the figure walking along the opposite side of the street I recognised my friend at once, though his coat collar was turned up and an immense yellow muffler hid the bottom part of his face. But there was no mistaking that walk, and the poise of that egg-shaped head.

It was Poirot, coming to my aid in all good faith, suspecting nothing amiss. By his side ran a typical London urchin, grimy of face and ragged of apparel.

Poirot paused, looking across at the house, whilst the boy spoke to him eagerly and pointed. It was the time for me to act. I went out in the hall. At a sign from the tall Chinaman, one of the servants unlatched the door.

"Remember the price of failure," said my enemy in a low voice.

I was outside on the steps. I beckoned to Poirot. He hastened across.

"Aha! So all is well with you, my friend. I was beginning to be anxious. You managed to get inside? Is the house empty, then?"

"Yes," I said, in a voice I strove to make natural. "There must be a secret way out of it somewhere. Come in and let us look for it."

I stepped back across the threshold. In all innocence Poirot prepared to follow me.

And then something seemed to snap in my head. I saw only too clearly the part I was playing—the part of Judas.

"Back, Poirot!" I cried. "Back for your life. It's a trap. Never mind me. Get away at once."

Even as I spoke—or rather shouted my warning hands gripped me like a vice. One of the Chinese servants sprang past me to grab Poirot.

I saw the latter spring back, his arm raised, then suddenly a dense volume of smoke was rising round me, choking me—killing me—

I felt myself falling—suffocating—this was death—

I came to myself slowly and painfully—all my senses dazed. The first thing I saw was Poirot's face. He was sitting opposite me watching me with an anxious face. He gave a cry of joy when he saw me looking at him.

"Ah, you revive—you return to yourself. All is well! My friend—my poor friend!"

"Where am I?" I said painfully.

"Where? But chez vous!"

I looked round me. True enough, I was in the old familiar surroundings. And in the grate were the identical four knobs of coal I had carefully spilt there.

Poirot had followed my glance.

"But yes, that was a famous idea of yours—that and the books. See you, if they should say to me any time. 'That friend of yours, that Hastings, he has not the great brain, is it not so?' I shall reply to them: 'You are in error.' It was an idea magnificent and superb that occurred to you there."

"You understood their meaning then?"

"Am I an imbecile? Of course I understood. It gave me just the warning I needed, and the time to mature my plans. Somehow or other the Big Four had carried you off. With what object? Clearly not for your beaux yeux—equally clearly not because they feared you and wanted to get you out of the way. No, their object was plain. You would be used as a decoy to get the great Hercule Poirot into their clutches. I have long been prepared for something of the kind. I make my little preparations, and presently, sure enough, the messenger arrives—such an innocent little street urchin. Me, I swallow everything, and hasten away with him, and, very fortunately, they permit you to come out on the doorstep. That was my one fear, that I should have to dispose of them before I had reached the place where you were concealed, and that I should have to search for you—perhaps in vain—afterwards."

"Dispose of them, did you say?" I asked feebly. "Single-handed."

"Oh, there is nothing very clever about that. If one is prepared in advance all is simple—the motto of the Boy Scout, is it not? And a very fine one. Me, I was prepared. Not so long ago, I rendered a service to a very famous chemist, who did a lot of work in connection with poison gas during the war. He devised for me a little bomb—simple and easy to carry about—one has but to throw it and poof, the smoke—and then the unconsciousness. Immediately I blow a little whistle and straightway some of Japp's clever fellows who were watching the house here long before the boy arrived, and who managed to follow us all the way to Limehouse, came flying up and took charge of the situation."

"But how was it you weren't unconscious too?"

"Another piece of luck. Our friend Number Four (who certainly composed that ingenious letter) permitted himself a little jest at my moustaches, which rendered it extremely easy for me to adjust my respirator under the guise of a yellow muffler."

"I remember," I cried eagerly, and then with the word "Remember" all the ghastly horror that I had temporarily forgotten came back to me. Cinderella—

I fell back with a groan.

I must have lost consciousness again for a minute or two. I awoke to find Poirot forcing some brandy between my lips.

"What is it, mon ami? But what is it—then? Tell me." Word by word, I got the thing told, shuddering as I did so. Poirot uttered a cry.

"My friend! My friend! But what you must have suffered! And I who knew nothing of all this! But reassure yourself! All is well!"

"You will find her, you mean? But she is in South America. And by the time we get there—long before, she will be dead—and God knows how and in what horrible way she will have died."

"No, no, you do not understand. She is safe and well. She has never been in their hands for one instant."

"But I got a cable from Bronsen?"

"No, no, you did not. You may have got a cable from South America signed Bronsen—that is a very different matter. Tell me, has it never occurred to you that an organisation of this kind, with ramifications all over the world, might easily strike at us through that little girl, Cinderella, whom you love so well?"

"No, never," I replied.

"Well, it did to me. I said nothing to you because I did not want to upset you unnecessarily—but I took measures of my own. Your wife's letters all seem to have been written from the ranch, but in reality she has been in a place of safety devised by me for over three months."

I looked at him for a long time.

"You are sure of that?"

"Parbleu! I know it. They tortured you with a lie!"

I turned my head aside. Poirot put his hand on my shoulder. There was something in his voice that I had never heard there before.

"You like not that I should embrace you or display the emotion, I know well. I will be very British. I will say nothing—but nothing at all. Only this—that in this last adventure of ours, the honours are all with you, and happy is the man who has such a friend as I have!"