My emotion, I am certain, was just as great as Noël Dorgeroux's and my heart beat no less violently. My curiosity had reached its utmost bounds; moreover, I had a formidable intuition that I was about to enter into a region of mystery of which nothing, not even my uncle's disconcerting words, was able to give me the remotest idea. I was experiencing the contagion of what seemed to me in him to be a diseased condition; and I vainly strove to subject it in myself to the control of my reason. I was taking the impossible and the incredible for granted beforehand.

And yet I saw nothing at first; and there was, in fact, nothing. This part of the wall was bare. The only detail worthy of remark was that it was not vertical and that the whole base of the wall had been thickened so as to form a slightly inclined plane which sloped upwards to a height of nine feet. What was the reason for this work, when the wall did not need strengthening?

A coating of dark grey plaster, about half an inch thick, covered the whole panel. When closely examined, however, it was not painted over, but was rather a layer of some substance uniformly spread and showing no trace of a brush. Certain gleams proved that this layer was quite recent, like a varnish newly applied. I observed nothing else; and Heaven knows that I did my utmost to discover any peculiarity!

"Well, uncle?" I asked.

"Wait," he said, in an agonized voice, "wait! . . . The first indication is beginning."

"What indication?"

"In the middle . . . like a diffused light. Do you see it?"

"Yes, yes, I think I do."

It was as when a little daylight is striving to mingle with the waning darkness. A lighter disk became marked in the middle of the panel; and this lighter shade spread towards the edges, while remaining more intense at its centre. So far there was no very decided manifestation of anything out of the way; the chemical reaction of a substance lately hidden by the curtain and now exposed to the daylight and the sun was quite enough to explain this sort of inner illumination. Yet something gave one the haunting though perhaps unreasonable impression that an extraordinary phenomenon was about to take place. For that was what I expected, as did my uncle Dorgeroux.

And all at once he, who knew the premonitory symptoms and the course of the phenomenon, started, as though he had received a shock.