there was nothing in it that could possibly upset any

one."

"You can repeat it, you say?" I encouraged her. 80 Agatha Christie

"Yes." She paused a minute and then repeated

slowly, whilst I noted down the words unobtrusively,

the following:-"dear sir,--The essential thing now, I should say, is to see the property. If you insist on the

quarry being included, then seventeen thousand

seems reasonable. 11% commission too much, 4%

is ample.

"Yours truly,

"arthur leversham."

Miss Martin went on:-"Evidently about some property Mr. Ryland was thinking of buying. But really, I do feel that a man who can get into a rage over such a trifle is, well, dangerous. What do you think I ought to do. Major Neville?

You've more experience of the world than I have."

I soothed the girl down, pointed out to her that Mr.

Ryland had probably been suffering from the enemy of

his race--dyspepsia. In the end I sent her away quite

comforted. But I was not so easily satisfied myself.

When the girl had gone, and I was alone, I took out my

notebook, and ran over the letter which I had jotted

down. What did it mean--this apparently innocentsounding missive? Did it concern some business deal

which Ryland was undertaking, and was he anxious that

no details about it should leak out until it was carried through? That was a possible explanation. But I remembered the small figure 4 with which the envelopes

were marked, and I felt that, at last, I was on the track of the thing we were seeking.

I puzzled over the letter all that evening, and most of

the next day--and then suddenly the solution came to

me. It was so simple, too. The figure 4 was the clue.

FR1;THE BIG FOUR 81

Read every fourth word in the letter, and an entirely different message appeared. "Essential should see you

quarry seventeen eleven four."

The solution of the figures was easy. Seventeen stood

for the seventeenth of October--which was tomorrow,

eleven was the time, and four was the signature--either

referring to the mysterious Number Four himself--or

else it was the "trade-mark" so to speak, of the Big Four. The quarry was also intelligible. There was a big

disused quarry on the estate about half a mile from the

house--a lonely spot, ideal for a secret meeting.

For a moment or two I was tempted to run the show

myself. It would be such a feather in my cap, for once,

to have the pleasure of crowing over Poirot.

But in the end I overcame the temptation. This was a

big business--I had no right to play a lone hand, and

perhaps jeopardise our chances of success. For the first time, we had stolen a march upon our enemies. We must

make good this time--and, disguise the fact as I might,

Poirot had the better brain of the two.

I wrote off post haste to him, laying the facts before

him, and explaining how urgent it was that we should