She knelt down by him, extracted his cigarette case,

took out a cigarette, and placed it between his lips.

"And now a match," she said, rising.

"It is not necessary, madame." Something in his voice startled me. She, too, was arrested.

"Do not move, I pray of you, madame. You will

regret it if you do. Are you acquainted at all with the

properties of cuare? The South American Indians use it

as an arrow poison. A scratch with it means death.

Some tribes use a little blow-pipe--I, too, have a little blow-pipe constructed so as to look exactly like a

cigarette. I have only to blow. ... Ah! you start. Do not move, madame. The mechanism of this cigarette is most

ingenious. One blows--and a tiny dart resembling a

fishbone flies through the air--to find its mark. You

do not wish to die, madame. Therefore, I beg of you,

release my friend Hastings from his bonds. I cannot use

my hands, but I can turn my head--so--you are still

covered, madame. Make no mistake, I beg of you."

Slowly, with shaking hands, and rage and hate convulsing her face, she bent down and did his bidding. I

was free. Poirot's voice gave me instructions.

"Your bonds will now do for the lady, Hastings. That is right. Is she securely fastened? Then release me, I

pray of you. It is a fortunate circumstance she sent away

THE BIG FOUR 71

her henchmen. With a little luck we may hope to find

the way out unobstructed."

In another minute, Poirot stood by my side. He

bowed to the lady.

"Hercule Poirot is not killed so easily, madame. I

wish you goodnight."

The gag prevented her from replying, but the murderous

gleam in her eyes frightened me. I hoped devoutly

that we should never fall into her power again.

Three minutes later we were outside the villa, and

hurriedly traversing the garden. The road outside was

deserted, and we were soon clear of the neighbourhood.

Then Poirot broke out.

"I deserve all that that woman said to me. I am a

triple imbecile, a miserable animal, thirty-six times

an idiot. I was proud of myself for not falling into their trap. And it was not even meant as a trap--except exactly in the way in which I fell into it. They knew

I would see through it--they counted on my seeing

through it. This explains all--the ease with which they

surrendered Halliday--everything. Madame Olivier was

the ruling spirit--Vera Rossakoff only her lieutenant.

Madame needed Halliday's ideas--she herself had the

necessary genius to supply the gaps that perplexed him.

Yes, Hastings, we know now who Number Three is-the woman who is probably the greatest scientist in the world! Think of it. The brain of the East, the science of the West--and two others whose identities we do not yet

know. But we must find out. To-morrow we will return

to London and set about it."

"You are not going to denounce Madame Olivier to