791815214. It will be a long time before I forget that number.
I examined the whole face of the metal rectangle with my lamp. A terrible disappointment was in store for me. Instead of the six knobs that I had expected I could only find two.
When a single factor throws out the kind of calculations I had just made it can only mean that one's theory is radically false. I might have known. That would have been much too simple....
Solely to prove myself wrong, I tried the first knob and turning the pointer on the dial I set it on the figure 7—g.
I crossed to the other side and repeated the operation on the other knob, putting the pointer on the figure 9—i.
All at once I could hear my heart beat. A black vertical line appeared in the centre of the plaque. That line got wider and wider. The two panels thus formed slid back to each side, leaving a gap some two feet six inches wide.
I was on the right track. The mystery of the Herrenhausen was to be solved at last!
I had recovered control of myself, perfect control. I remember saying: "What a delightful way of studying history! I wonder what Monsieur Seignobos would think of it?"
I passed through the opening, taking with me the stool which had been my table. On the inside the fire-back had two handles, one on each side. Very gently, but quite easily, I drew the panels together again, not absolutely touching, however, for fear of releasing some fatal spring.
Do you remember the 24th August, my friend, in the village of Beaumont, in Belgium, when you and I went down into a cellar where the inhabitants said five Uhlans were hiding? You called me a rash fool and came behind, but I couldn't help smiling at the thought that those five fugitives were nothing compared with the darkness in which I was wrapped that night.