Even now I can hardly bear to write of those days in March.

Poirot—the unique, the inimitable Hercule Poirot—dead! There was a particularly diabolical touch in the disarranged match-box, which was certain to catch his eye, and which he would hasten to rearrange—and thereby touch off the explosion. That, as a matter of fact, it was I who actually precipitated the catastrophe never ceased to fill me with unavailing remorse. It was, as Doctor Ridgeway said, a perfect miracle that I had not been killed, but had escaped with a slight concussion.

Although it had seemed to me as though I regained consciousness almost immediately, it was in reality over twenty-four hours before I came back to life. It was not until the evening of the day following that I was able to stagger feebly into an adjoining room, and view with deep emotion the plain elm coffin which held the remains of one of the most marvellous men this world has ever known.

From the very first moment of regaining consciousness I had only one purpose in mind—to avenge Poirot's death, and to hunt down the Big Four remorselessly.

I had thought that Ridgeway would have been of one mind with me about this, but to my surprise the good doctor seemed unaccountably lukewarm.

"Get back to South America" was his advice, tendered on every occasion. Why attempt the impossible? Put as delicately as possible, his opinion amounted to this:—If Poirot, the unique Poirot, had failed, was it likely that I should succeed?

But I was obstinate. Putting aside any question as to whether I had the necessary qualifications for the task (and I may say in passing that I did not entirely agree with his views on this point), I had worked so long with Poirot that I knew his methods by heart, and felt fully capable of taking up the work where he had laid it down; it was, with me, a question of feeling. My friend had been foully murdered. Was I to go tamely back to South America without an effort to bring his murderers to justice?

I said all this and more to Ridgeway, who listened attentively enough.

"All the same," he said when I had finished, "my advice does not vary. I am earnestly convinced that Poirot himself, if he were here, would urge you to return. In his name, I beg of you, Hastings, abandon these wild ideas and go back to your ranch."

To that only one answer was possible, and, shaking his head sadly, he said no more.

It was a month before I was fully restored to health. Towards the end of April, I sought, and obtained, an interview with the Home Secretary.

Mr. Crowther's manner was reminiscent of that of Dr. Ridgeway. It was soothing and negative. Whilst appreciating the offer of my services, he gently and considerately declined them. The papers referred to by Poirot had passed into his keeping, and he assured me that all possible steps were being taken to deal with the approaching menace.

With that cold comfort I was forced to be satisfied. Mr. Crowther ended the interview by urging me to return to South America. I found the whole thing profoundly unsatisfactory.

I should, I suppose, in its proper place, have described Poirot's funeral. It was a solemn and moving ceremony, and the extraordinary number of floral tributes passed belief. They came from high and low alike, and bore striking testimony to the place my friend had made for himself in the country of his adoption. For myself, I was frankly overcome by emotion as I stood by the grave side and thought of all our varied experiences and the happy days we had passed together.

By the beginning of May I had mapped out a plan of campaign. I felt that I could not do better than keep Poirot's scheme of advertising for any information respecting Claud Darrell. I had an advertisement to this effect inserted in a number of morning newspapers, and I was sitting in a small restaurant in Soho, and judging of the effect of the advertisement, when a small paragraph in another part of the paper gave me a nasty shock.

Very briefly, it reported the mysterious disappearance of Mr. John Ingles from the S.S. Shanghai shortly after the latter had left Marseilles. Although the weather was perfectly smooth, it was feared that the unfortunate gentleman must have fallen overboard. The paragraph ended with a brief reference to Mr. Ingles's long and distinguished service in China.

The news was unpleasant. I read into Ingles's death a sinister motive. Not for one moment did I believe the theory of an accident. Ingles had been murdered, and his death was only too clearly the handiwork of that accursed Big Four.

As I sat there, stunned by the blow, and turning the whole matter over in my mind, I was startled by the remarkable behaviour of the man sitting opposite me. So far I had not paid much attention to him. He was a thin, dark man of middle age, sallow of complexion, with a small pointed beard. He had sat down opposite me so quietly that I had hardly noticed his arrival.

But his actions now were decidedly peculiar, to say the least of them. Leaning forward, he deliberately helped me to salt, putting it in four little heaps round the edge of my plate.

"You will excuse me," he said, in a melancholy voice. "To help a stranger to salt is to help them to sorrow, they say. That may be an unavoidable necessity. I hope not, though. I hope that you will be reasonable."

Then, with a certain significance, he repeated his operations with the salt on his own plate. The symbol 4 was too plain to be missed. I looked at him searchingly. In no way that I could see did he resemble young Templeton, or James the footman, or any other of the various personalities we had come across. Nevertheless, I was convinced that I had to do with no less than the redoubtable Number Four himself. In his voice there was certainly a faint resemblance to the buttoned-up-stranger who had called upon us in Paris.

I looked round, undecided as to my course of action. Reading my thoughts, he smiled and gently shook his head.

"I should not advise it," he remarked. "Remember what came of your hasty action in Paris. Let me assure you that my way of retreat is well assured. Your ideas are inclined to be a little crude, Captain Hastings, if I may say so."

"You devil," I said, choking with rage, "you incarnate devil!"

"Heated—just a trifle heated. Your late lamented friend would have told you that a man who keeps calm has always a great advantage."

"You dare to speak of him," I cried. "The man you murdered so foully. And you come here—"

He interrupted me.

"I came here for an excellent and peaceful purpose. To advise you to return at once to South America. If you do so, that is the end of the matter as far as the Big Four are concerned. You and yours will not be molested in any way. I give you my word as to that."

I laughed scornfully.

"And if I refuse to obey your autocratic command?"

"It is hardly a command. Shall we say that it is—a warning?"

There was a cold menace in his tone.

"The first warning," he said softly. "You will be well advised not to disregard it."

Then, before I had any hint of his intention, he rose and slipped quickly away towards the door. I sprang to my feet and was after him in a second, but by bad luck I cannoned straight into an enormously fat man who blocked the way between me and the next table. By the time I had disentangled myself, my quarry was just passing through the doorway, and the next delay was from a waiter carrying a huge pile of plates who crashed into me without the least warning. By the time I got to the door there was no sign of the thin man with the dark beard.

The waiter was fulsome in apologies, the fat man was sitting placidly at a table ordering his lunch. There was nothing to show that both occurrences had not been a pure accident. Nevertheless, I had my own opinion as to that. I knew well enough that the agents of the Big Four were everywhere.

Needless to say, I paid no heed to the warning given me. I would do or die in the good cause. I received in all only two answers to the advertisements. Neither of them gave me any information of value. They were both from actors who had played with Claud Darrell at one time or another. Neither of them knew him at all intimately, and no new light was thrown upon the problem of his identity and present whereabouts.

No further sign came from the Big Four until about ten days later. I was crossing Hyde Park, lost in thought, when a voice, rich with a persuasive foreign inflection, hailed me.

"Captain Hastings, is it not?"

A big limousine had just drawn up by the pavement. A woman was leaning out. Exquisitely dressed in black, with wonderful pearls, I recognised the lady first known to us as Countess Vera Rossakoff, and afterwards under a different alias as an agent of the Big Four. Poirot, for some reason or other, had always had a sneaking fondness for the countess. Something in her very flamboyance attracted the little man. She was, he was wont to declare in moments of enthusiasm, a woman in a thousand. That she was arrayed against us, on the side of our bitterest enemies, never seemed to weigh in his judgment. "Ah, do not pass on!" said the countess. "I have something most important to say to you. And do not try to have me arrested either, for that would be stupid. You were always a little stupid—yes, yes, it is so. You are stupid now, when you persist in disregarding the warning we sent you. It is the second warning I bring you. Leave England at once. You can do no good here—I tell you that frankly. You will never accomplish anything."

"In that case," I said stiffly, "it seems rather extraordinary that you are all so anxious to get me out of the country."

The countess shrugged her shoulders—magnificent shoulders, and a magnificent gesture.

"For my part, I think that, too, stupid. I would leave you here to play about happily. But the chiefs, you see, are fearful that some word of yours may give great help to those more intelligent than yourself. Hence—you are to be banished."

The countess appeared to have a flattering idea of my abilities. I concealed my annoyance. Doubtless this attitude of hers was assumed expressly to annoy me and to give me the idea that I was unimportant.

"It would, of course, be quite easy to—remove you," she continued, "but I am quite sentimental sometimes. I pleaded for you. You have a nice little wife somewhere, have you not? And it would please the poor little man who is dead to know that you were not to be killed. I always liked him, you know. He was clever—but clever! Had it not been a case of four against one I honestly believe he might have been too much for us. I confess it frankly—he was my master! I sent a wreath to the funeral as a token of my admiration—an enormous one of crimson roses. Crimson roses express my temperament."

I listened in silence and a growing distaste.

"You have the look of a mule when it puts its ears back and kicks. Well, I have delivered my warning. Remember this, the third warning will come by the hand of the Destroyer—"

She made a sign, and the car whirled away rapidly. I noted the number mechanically, but without the hope that it would lead to anything. The Big Four were not apt to be careless in details.

I went home a little sobered. One fact had emerged from the countess's flood of volubility. I was in real danger of my life. Though I had no intention of abandoning the struggle, I saw that it behoved me to walk warily and adopt every possible precaution.

Whilst I was reviewing all these facts and seeking for the best line of action, the telephone bell rang. I crossed the room and picked up the receiver.

"Yes. Hallo. Who's speaking?"

A crisp voice answered me.

"This is St. Giles' Hospital. We have a Chinaman here, knifed in the street and brought in. He can't last long. We rang you up because we found in his pocket a piece of paper with your name and address on it."

I was very much astonished. Nevertheless, after a moment's reflection I said that I would come down at once. St. Giles' Hospital was, I knew, down by the docks, and it occurred to me that the Chinaman might have just come off some ship.

It was on my way down there that a sudden suspicion shot into my mind. Was the whole thing a trap? Wherever a Chinaman was, there might be the hand of Li Chang Yen. I remembered the adventure of the Baited Trap. Was the whole thing a ruse on the part of my enemies?

A little reflection convinced me that at any rate a visit to the hospital would do no harm. It was probable that the thing was not so much a plot as what is vulgarly known as a "plant." The dying Chinaman would make some revelation to me upon which I should act, and which would have the result of leading me into the hands of the Big Four. The thing to do was to preserve an open mind, and whilst feigning credulity be secretly on my guard.

On arriving at St. Giles' Hospital, and making my business known, I was taken at once to the accident ward, to the bedside of the man in question. He lay absolutely still, his eyelids closed, and only a very faint movement of the chest showed that he still breathed. A doctor stood by the bed, his fingers on the Chinaman's pulse.

"He's almost gone," he whispered to me. "You know him, eh?"

I shook my head.

"I've never seen him before."

"Then what was he doing with your name and address in his pocket? You are Captain Hastings, aren't you?"

"Yes, but I can't explain it any more than you can."

"Curious thing. From his papers he seems to have been the servant of a man called Ingles—a retired Civil Servant. Ah, you know him, do you?" he added quickly, as I started at the name.

Ingles's servant! Then I had seen him before. Not that I had ever succeeded in being able to distinguish one Chinaman from another. He must have been with Ingles on his way to China, and after the catastrophe he had returned to England with a message, possibly, for me. It was vital, imperative that I should hear that message.

"Is he conscious?" I asked. "Can he speak? Mr. Ingles was an old friend of mine, and I think it possible that this poor fellow has brought me a message from him. Mr. Ingles is believed to have gone overboard about ten days ago."

"He's just conscious, but I doubt if he has the force to speak. He lost a terrible lot of blood, you know. I can administer a stimulant, of course, but we've already done all that is possible in that direction."

Nevertheless, he administered a hypodermic injection, and I stayed by the bed, hoping against hope for a word—a sign—that might be of the utmost value to me in my work. But the minutes sped on and no sign came.

And suddenly a baleful idea shot across my mind? Was I not already falling into the trap? Suppose that this Chinaman had merely assumed the part of Ingles's servant, that he was in reality an agent of the Big Four? Had I not once read that certain Chinese priests were capable of simulating death? Or, to go further still, Li Chang Yen might command a little band of fanatics who would welcome death itself if it came at the command of their master. I must be on my guard.

Even as these thoughts flashed across my mind, the man in the bed stirred. His eyes opened. He murmured something incoherently. Then I saw his glance fasten upon me. He made no sign of recognition, but I was at once aware that he was trying to speak to me. Be he friend or foe, I must hear what he had to say.

I leaned over the bed, but the broken sounds conveyed no sort of meaning to me. I thought I caught the word "hand," but in what connection it was used I could not tell. Then it came again, and this time I heard another word, the word "Largo." I stared in amazement, as the possible juxtaposition of the two suggested itself to me.

"Handel's Largo?" I queried.

The Chinaman's eyelids flickered rapidly, as though in assent, and he added another Italian word, the word "carrozza." Two or three more words of murmured Italian came to my ears, and then he fell back abruptly.

The doctor pushed me aside. It was all over. The man was dead.

I went out into the air again thoroughly bewildered.

"Handel's Largo," and a "carrozza." If I remembered rightly, a carrozza was a carriage. What possible meaning could lie behind those simple words. The man was a Chinaman, not an Italian, why should he speak in Italian? Surely, if he were indeed Ingles's servant, he must know English? The whole thing was profoundly mystifying. I puzzled over it all the way home. Oh, if only Poirot had been there to solve the problem with his lightning ingenuity!

I let myself in with my latch-key and went slowly up to my room. A letter was lying on the table, and I tore it open carelessly enough. But in a minute I stood rooted to the ground whilst I read.

It was a communication from a firm of solicitors.

"Dear Sir (it ran),—As instructed by our late client, M. Hercule Poirot, we forward you the enclosed letter. This letter was placed in our hands a week before his death, with instructions that in the event of his demise, it should be sent to you at a certain date after his death.

"Yours faithfully, etc."

I turned the enclosed missive over and over. It was undoubtedly from Poirot. I knew that familiar writing only too well. With a heavy heart, yet a certain eagerness, I tore it open.

"Mon Cher Ami (it began),—When you receive this I shall be no more. Do not shed tears about me, but follow my orders. Immediately upon receipt of this, return to South America. Do not be pig-headed about this. It is not for sentimental reasons that I bid you undertake the journey. It is necessary. It is part of the plan of Hercule Poirot! To say more is unnecessary, to any one who has the acute intelligence of my friend Hastings.

"A bas the Big Four! I salute you, my friend, from beyond the grave.

"Ever thine,

"Hercule Poirot."

I read and re-read this astonishing communication. One thing was evident. This amazing man had so provided for every eventuality that even his own death did not upset the sequence of his plans! Mine was to be the active part—his the directing genius. Doubtless I should find full instructions awaiting me beyond the seas. In the meantime my enemies, convinced that I was obeying their warning, would cease to trouble their heads about me. I could return, unsuspected, and work havoc in their midst.

There was now nothing to hinder my immediate departure. I sent off cables, booked my passage, and one week later found me embarking in the Ansonia en route for Buenos Ayres.

Just as the boat left the quay, a steward brought me a note. It had been given him, so he explained, by a big gentleman in a fur coat who had left the boat last thing before the gangway planks were lifted.

I opened it. It was terse and to the point.

"You are wise," it ran. It was signed with a big figure 4.

I could afford to smile to myself!

The sea was not too choppy. I enjoyed a passable dinner, made up my mind as to the majority of my fellow passengers, and had a rubber or two of Bridge. Then I turned in and slept like a log as I always do on board ship.

I was awakened by feeling myself persistently shaken. Dazed and bewildered, I saw that one of the ship's officers was standing over me. He gave a sigh of relief as I sat up.

"Thank the Lord I've got you awake at last. I've had no end of a job. Do you always sleep like that?"

"What's the matter?" I asked, still bewildered and not fully awake. "Is there anything wrong with the ship?"

"I expect you know what's the matter better than I do," he replied dryly. "Special instructions from the Admiralty. There's a destroyer waiting to take you off."

"What?" I cried. "In mid-ocean?"

"It seems a most mysterious affair, but that's not my business. They've sent a young fellow aboard who is to take your place, and we are all sworn to secrecy. Will you get up and dress?"

Utterly unable to conceal my amazement I did as I was told. A boat was lowered, and I was conveyed aboard the destroyer. There I was received courteously, but got no further information. The commander's instructions were to land me at a certain spot on the Belgian coast. There his knowledge and responsibility ended.

The whole thing was like a dream. The one idea I held to firmly was that all this must be part of Poirot's plan. I must simply go forward blindly, trusting in my dead friend.

I was duly landed at the spot indicated. There a motor was waiting, and soon I was rapidly whirling along across the flat Flemish plains. I slept that night at a small hotel in Brussels. The next day we went on again. The country became wooded and hilly. I realised that we were penetrating into the Ardennes, and I suddenly remembered Poirot's saying that he had a brother who lived at Spa.

But we did not go to Spa itself. We left the main road and wound into the leafy fastnesses of the hills, till we reached a little hamlet, and an isolated white villa high on the hill-side. Here the car stopped in front of the green door of the villa.

The door opened as I alighted. An elderly man-servant stood in the doorway bowing.

"M. le Capitaine Hastings?" he said in French. "Monsieur le Capitaine is expected. If he will follow me."

He led the way across the hall, and flung open a door at the back, standing aside to let me pass in.

I blinked a little, for the room faced west and the afternoon sun was pouring in. Then my vision cleared and I saw a figure waiting to welcome me with outstretched hands.

It was—oh, impossible, it couldn't be—but yes!

"Poirot!" I cried, and for once did not attempt to evade the embrace with which he overwhelmed me.

"But yes, but yes, it is indeed I! Not so easy to kill Hercule Poirot!"

"But Poirot—why?"

"A ruse de guerre, my friend, a ruse de guerre. All is now ready for our grand coup."

"But you might have told me!"

"No, Hastings, I could not. Never, never, in a thousand years, could you have acted the part at the funeral. As it was, it was perfect. It could not fail to carry conviction to the Big Four."

"But what I've been through—"

"Do not think me too unfeeling. I carried out the deception partly for your sake. I was willing to risk my own life, but I had qualms about continually risking yours. So, after the explosion, I have an idea of great brilliancy. The good Ridgeway, he enables me to carry it out. I am dead, you will return to South America. But, mon ami, that is just what you would not do. In the end I have to arrange a solicitor's letter, and a long rigmarole. But, at all events, here you are—that is the great thing. And now we lie here—perdu—till the moment comes for the last grand coup—the final overthrowing of the Big Four."