The Bel-Air, that top story of the New Building, was a sort of large hall, with a Mansard roof, guarded with triple gratings and double doors of sheet iron, which were studded with enormous bolts. When one entered from the north end, one had on one’s left the four dormer-windows, on one’s right, facing the windows, at regular intervals, four square, tolerably vast cages, separated by narrow passages, built of masonry to about the height of the elbow, and the rest, up to the roof, of iron bars.

Thénardier had been in solitary confinement in one of these cages since the night of the 3rd of February. No one was ever able to discover how, and by what connivance, he succeeded in procuring, and secreting a bottle of wine, invented, so it is said, by Desrues, with which a narcotic is mixed, and which the band of the Endormeurs , or “Sleep-compellers,” rendered famous.

There are, in many prisons, treacherous employees, half-jailers, half-thieves, who assist in escapes, who sell to the police an unfaithful service, and who turn a penny whenever they can.