He was starting to keep the appointment.
I redoubled my pace, so as to get a clear start.
I arrived at the quarry somewhat out of breath.
There seemed no one about, and I crawled into a thick tangle of bushes and awaited developments.
Ten minutes later, just on the stroke of eleven, Ryland stalked up, his hat over his eyes and the inevitable cigar in his mouth.
He gave a quick look round, and then plunged into the hollows of the quarry below.
Presently I heard a low murmur of voices come up to me.
Evidently the other man - or men - whoever they were, had arrived first at the rendezvous.
I crawled cautiously out of the bushes, and inch by inch, using the utmost precaution against noise, I wormed myself down the steep path.
Only a boulder now separated me from the talking men.
Secure in the blackness, I peeped round the edge of it and found myself facing the muzzle of a black, murderous-looking automatic!
"Hands up!" said Mr. Ryland succinctly. "I've been waiting for you."
He was seated in the shadow of the rock, so that I could not see his face, but the menace in his voice was unpleasant.
Then I felt a ring of cold steel on the back of my neck, and Ryland lowered his own automatic.
"That's right, George," he drawled. "March him around here."
Raging inwardly, I was conducted to a spot in the shadows, where the unseen George (whom I suspected of being the impeccable Deaves), gagged and bound me securely.
Ryland spoke again in a tone which I had difficulty in recognising, so cold and menacing was it.
"This is going to be the end of you two.
You've got in the way of the Big Four once too often.
Ever heard of land slides?
There was one about here two years ago.
There's going to be another tonight.
I've fixed that good and square.
Say, that friend of yours doesn't keep his dates very punctually."
A wave of horror swept over me.
Poirot!
In another minute he would walk straight into the trap.
And I was powerless to warn him.
I could only pray that he had elected to leave the matter in my hands, and had remained in London.
Surely, if he had been coming, he would have been here by now.
With every minute that passed, my hopes rose.
Suddenly they were dashed to pieces.
I heard footsteps - cautious footsteps, but footsteps nevertheless.
I writhed in impotent agony.
They came down the path, paused, and then Poirot himself appeared, his head a little on one side, peering into the shadows.
I heard the growl of satisfaction Ryland gave as he raised the big automatic and shouted
"Hands up."
Deaves sprang forward as he did so, and took Poirot in the rear.
The ambush was complete.
"Please to meet you, Mr. Hercule Poirot," said the American grimly.
Poirot's self-possession was marvellous.
He did not turn a hair.
But I saw his eyes searching in the shadows.
"My friend?
He is here?"
"Yes, you are both in the trap - the trap of the Big Four." He laughed.
"A trap?" queried Poirot.
"Say, haven't you tumbled to it yet?"
"I comprehend that there is a trap - yes," said Poirot gently. "But you are in error, monsieur.
It is you who are in it - not I and my friend."