Jean Valjean found himself in presence of a fontis: this sort of breaking-in was frequent at that day in the subsoil of the Champs Élysées, which was difficult to manage in hydraulic works, and not preservative of subterranean constructions, owing to its extreme fluidity. This fluidity exceeds even the inconsistency of the sands of the Quartier St. Georges, which could only be overcome by laying rubble on béton, and of the gas-infected clay strata in the Quartier des Martyrs, which are so liquid that a passage could be effected under the gallery only by means of an iron tube. When in 1836 the authorities demolished and rebuilt under the Faubourg St. Honoré the old stone sewer in which Jean Valjean is now engaged, the shifting sand which is the subsoil of the Champs Élysées as far as the Seine offered such an obstacle that the operation lasted six months, to the great annoyance of those living on the water-side, especially such as had mansions and coaches. The works were more than difficult, they were dangerous; but we must allow that it rained for four and a half months, and the Seine overflowed thrice. The fontis which Jean Valjean came across was occasioned by the shower of the previous evening. A giving way of the pavement, which was badly supported by the subjacent sand, had produced a deposit of rain-water, and when the filtering had taken place the ground broke in, and the roadway, being dislocated, fell into the mud. How far? It was impossible to say, for the darkness was denser there than anywhere else; it was a slough of mud in a cavern of night. Jean Valjean felt the pavement depart from under him as he entered the slough; there was water at top and mud underneath. He must pass it, for it was impossible to turn back; Marius was dying, and Jean Valjean worn out. Where else could he go? Jean Valjean advanced; the slough appeared but of slight depth at the first few steps, but as he advanced his legs sank in. He soon had mud up to the middle of the leg, and water up to the middle of the knee. He walked along, raising Marius with both arms as high as he could above the surface of the water; the mud now came up to his knees and the water to his waist. He could no longer draw back, and he sank in deeper and deeper. This mud, dense enough for the weight of one man, could not evidently bear two; Marius and Jean Valjean might have had a chance of getting out separately; but, for all that, Jean Valjean continued to advance, bearing the dying man, who was perhaps a corpse. The water came up to his armpits, and he felt himself drowning; he could scarce move in the depth of mud in which he was standing, for the density which was the support was also the obstacle. He still kept Marius up, and advanced with an extraordinary expenditure of strength, but he was sinking. He had only his head out of water and his two arms sustaining Marius. In the old paintings of the Deluge there is a mother holding her child in the same way.