In the recess containing the window, the lower part of the wall, which formed a very wide box underneath the casement, had the top of its woodwork raised and resting against the panes, exactly like the lid of a chest.  And inside the open chest he saw the upper rungs of a narrow descending ladder.

In a second, Don Luis conjured up the whole story of the past:  Count Malonyi’s ancestress hiding in the old family mansion, escaping the search of the perquisitors, and in this way living throughout the revolutionary troubles.  Everything was explained.  A passage contrived in the thickness of the wall led to some distant outlet.  And this was how Florence used to come and go through the house; this was how Gaston went in and out in all security; and this also was how both of them were able to enter his room and surprise his secrets.

“Why not have told me?” he wondered.  “A lingering suspicion, I suppose—­”

But his eyes were attracted by a sheet of paper on the table.  With a feverish hand, Gaston Sauverand had scribbled the following lines in pencil: 

“We are trying to escape so as not to compromise you.  If we are caught, it can’t be helped.  The great thing is that you should be free.  All our hopes are centred in you.”

Below were two words written by Florence:  “Save Marie.”

“Ah,” he murmured, disconcerted by the turn of events and not knowing what to decide, “why, oh, why did they not obey my instructions?  We are separated now—­”

Downstairs the detectives were battering at the door of the passage in which they were imprisoned.  Perhaps he would still have time to reach his motor before they succeeded in breaking down the door.  Nevertheless, he preferred to take the same road as Florence and Sauverand, which gave him the hope of saving them and of rescuing them in case of danger.

He therefore stepped over the side of the chest, placed his foot on the top rung and went down.  Some twenty bars brought him to the middle of the first floor.  Here, by the light of his electric lantern, he entered a sort of low, vaulted tunnel, dug, as he thought, in the wall, and so narrow that he could only walk along it sideways.

Thirty yards farther there was a bend, at right angles; and next, at the end of another tunnel of the same length, a trapdoor, which stood open, revealing the rungs of a second ladder.  He did not doubt that the fugitives had gone this way.

It was quite light at the bottom.  Here he found himself in a cupboard which was also open and which, on ordinary occasions, must have been covered by curtains that were now drawn.  This cupboard faced a bed that filled almost the whole space of an alcove.  On passing through the alcove and reaching a room from which it was separated only by a slender partition, to his great surprise, he recognized Florence’s sitting-room.

This time, he knew where he was.  The exit, which was not secret, as it led to the Place du Palais-Bourbon, but nevertheless very safe, was that which Sauverand generally used when Florence admitted him.