His eyes and the tips of his ears were all that could be seen of him.
I did not know whether this was due to precaution or merely his exaggerated fear of catching a chill.
The motor journey took a couple of hours.
It was a really wonderful drive.
For the first part of the way we wound in and out of huge cliffs, with a trickling waterfall on one hand.
Then we emerged into a fertile valley, which continued for some miles, and then, still winding steadily upwards, the bare rocky peaks began to show with dense clustering pinewoods at their base.
The whole place was wild and lovely.
Finally a series of abrupt curves, with the road running through the pine woods on either side, and we came suddenly upon a big hotel and found that we had arrived.
Our rooms had been reserved for us, and under Harvey's guidance we went straight up to them.
They looked straight out over the rocky peaks and the long slopes of pine woods leading up to them.
Poirot made a gesture towards them.
"It is there?" he asked in a low voice.
"Yes," replied Harvey. "There is a place called the Felsenlabyrynth - all big boulders piled about in a most fantastic way - a path winds through them.
The quarrying is to the right of that, but we think that the entrance is probably in the Felsenlabyrynth."
Poirot nodded.
"Come, mon ami" he said to me. "Let us go down and sit upon the terrace and enjoy the sunlight."
"You think that wise?" I asked.
He shrugged his shoulders.
The sunlight was marvellous - in fact the glare was almost too great for me.
We had some creamy coffee instead of tea, then went upstairs and unpacked our few belongings.
Poirot was in his most unapproachable mood, lost in a kind of reverie.
Once or twice he shook his head and sighed.
I had been rather intrigued by a man who had got out of our train at Bolzano, and had been met by a private car.
He was a small man, and the thing about him that had attracted my attention was that he was almost as much muffled up as Poirot had been.
More so, indeed, for in addition to greatcoat and muffler, he was wearing huge blue spectacles.
I was convinced that here we had an emissary of the Big Four.
Poirot did not seem very impressed by my idea, but when, leaning out of my bedroom window, I reported that the man in question was strolling about in the vicinity of the hotel, he admitted that there might be something in it.
I urged my friend not to go down to dinner, but he insisted on doing so.
We entered the dining-room rather late, and were shown to a table by the window.
As we sat down, our attention was attracted by an exclamation and a crash of falling china.
A dish of haricots verts had been upset over a man who was sitting at the table next to ours.
The head waiter came up and was vociferous in apologies.
Presently, when the offending waiter was serving us with soup, Poirot spoke to him.
"An unfortunate accident, that.
But it was not your fault."
"Monsieur saw that?
No, indeed it was not my fault.
The gentleman half sprung up from his chair - I thought he was going to have an attack of some kind.
I could not save the catastrophe."
I saw Poirot's eyes shining with the green light I knew so well, and as the waiter departed he said to me in a low voice:
"You see, Hastings, the effect of Hercule Poirot - alive and in the flesh?"
"You think -" I had not time to continue. I felt Poirot's hand on my knee, as he whispered excitedly:
"Look, Hastings, look.
His trick with the bread!
Number Four!"
Sure enough, the man at the next table to ours, his face unusually pale, was dabbing a small piece of bread mechanically about the table.
I studied him carefully.
His face, clean-shaven and puffily fat, was of a pasty, unhealthy sallowness, with heavy pouches under the eyes and deep lines running from his nose to the corners of his mouth.
His age might have been anything from thirty-five to forty-five.
In no particular did he resemble any one of the characters which Number Four had previously assumed.