was on the eve of success in his experiments.â
âEh bien?â demanded Poirot, with interest.
âIt was suggested that I should come over here and get an interview with this gentleman. Quite a young fellow, he is, Halliday by name. He is the leading authority on the subject, and I was to get from him whether the thing suggested was anyway possible.â
âAnd was it?â I asked eagerly.
âThatâs just what I donât know. I havenât seen Mr. Hallidayâand Iâm not likely to, by all accounts.â
âThe truth of the matter is,â said Japp shortly, âHallidayâs disappeared.â
âWhen?â
âTwo months ago.â
âWas his disappearance reported?â
âOf course it was. His wife came to us in a great state. We did what we could, but I knew all along it would be no good.â
âWhy not?â
âNever isâwhen a man disappears that way.â Japp winked.
âWhat way?â
âParis.â
âSo Halliday disappeared in Paris?â
âYes. Went over there on scientific workâso he said. Of course, heâd have to say something like that. But you know what it means when a man disappears over there. Either itâs Apache work, and thatâs the end of itâor else itâs voluntary disappearanceâandthatâs a great deal the commoner of the two, I can tell you. Gay Paree and all that, you know. Sick of home life. Halliday and his wife had had a tiff before he started, which all helps to make it a pretty clear case.â
âI wonder,â said Poirot thoughtfully.
The American was looking at him curiously.
âSay, mister,â he drawled, âwhatâs this Big Four idea?â
âThe Big Four,â said Poirot, âis an international organization which has at its head a Chinaman. He is known as Number One. Number Two is an American. Number Three is a Frenchwoman. Number Four, âthe Destroyer,â is an Englishman.â
âA Frenchwoman, eh?â The American whistled. âAnd Halliday disappeared in France. Maybe thereâs something in this. Whatâs her name?â
âI donât know. I know nothing about her.â
âBut itâs a mighty big proposition, eh?â suggested the other.
Poirot nodded, as he arranged the glasses in a neat row on the tray. His love of order was as great as ever.
âWhat was the idea in sinking those boats? Are the Big Four a German stunt?â
âThe Big Four are for themselvesâand for themselves only, M. le Capitaine. Their aim is world domination.â
The American burst out laughing, but broke off at the sight of Poirotâs serious face.
âYou laugh, monsieur,â said Poirot, shaking a finger at him. âYou reflect notâyou use not the little grey cells of the brain. Who are these men who send a portion of your navy to destruction simply as a trial of their power? For that was all it was, Monsieur, a test of this new force of magnetical attraction which they hold.â
âGo on with you, moosior,â said Japp good-humouredly. Iâve read of supercriminals many a time, but Iâve never come across them. Well, youâve heard Captain Kentâs story. Anything further I can do for you?â
âYes, my good friend. You can give me the address of Mrs. Hallidayâand also a few words of introduction to her if you will be so kind.â
Thus it was that the following day saw us bound for Chetwynd Lodge, near the village of Chobham in Surrey.
Mrs. Halliday received us at once, a tall, fair woman, nervous and eager in manner. With her was her little girl, a beautiful child of five.
Poirot explained the purpose of our visit.
âOh! M. Poirot, I am so glad, so thankful. I have heard of you, of course. You will not be like these Scotland Yard people, who will not listen or try to understand. And the French police are just as badâworse, I