Jean Valjean found himself in the presence of a fontis.
This sort of quagmire was common at that period in the subsoil of the Champs-Elysees, difficult to handle in the hydraulic works and a bad preservative of the subterranean constructions, on account of its excessive fluidity. This fluidity exceeds even the inconsistency of the sands of the Quartier Saint-Georges, which could only be conquered by a stone construction on a concrete foundation, and the clayey strata, infected with gas, of the Quartier des Martyrs, which are so liquid that the only way in which a passage was effected under the gallery des Martyrs was by means of a cast-iron pipe. When, in 1836, the old stone sewer beneath the Faubourg Saint-Honore, in which we now see Jean Valjean, was demolished for the purpose of reconstructing it, the quicksand, which forms the subsoil of the Champs-Elysees as far as the Seine, presented such an obstacle, that the operation lasted nearly six months, to the great clamor of the dwellers on the riverside, particularly those who had hotels and carriages. The work was more than unhealthy; it was dangerous. It is true that they had four months and a half of rain, and three floods of the Seine.
The fontis which Jean Valjean had encountered was caused by the downpour of the preceding day. The pavement, badly sustained by the subjacent sand, had given way and had produced a stoppage of the water. Infiltration had taken place, a slip had followed. The dislocated bottom had sunk into the ooze. To what extent? Impossible to say. The obscurity was more dense there than elsewhere. It was a pit of mire in a cavern of night.
Jean Valjean felt the pavement vanishing beneath his feet. He entered this slime. There was water on the surface, slime at the bottom. He must pass it. To retrace his steps was impossible. Marius was dying, and Jean Valjean exhausted. Besides, where was he to go? Jean Valjean advanced. Moreover, the pit seemed, for the first few steps, not to be very deep. But in proportion as he advanced, his feet plunged deeper. Soon he had the slime up to his calves and water above his knees. He walked on, raising Marius in his arms, as far above the water as he could. The mire now reached to his knees, and the water to his waist. He could no longer retreat. This mud, dense enough for one man, could not, obviously, uphold two. Marius and Jean Valjean would have stood a chance of extricating themselves singly. Jean Valjean continued to advance, supporting the dying man, who was, perhaps, a corpse.
The water came up to his arm-pits; he felt that he was sinking; it was only with difficulty that he could move in the depth of ooze which he had now reached. The density, which was his support, was also an obstacle. He still held Marius on high, and with an unheard-of expenditure of force, he advanced still; but he was sinking. He had only his head above the water now and his two arms holding up Marius. In the old paintings of the deluge there is a mother holding her child thus.
He sank still deeper, he turned his face to the rear, to escape the water, and in order that he might be able to breathe; anyone who had seen him in that gloom would have thought that what he beheld was a mask floating on the shadows; he caught a faint glimpse above him of the drooping head and livid face of Marius; he made a desperate effort and launched his foot forward; his foot struck something solid; a point of support. It was high time.
He straightened himself up, and rooted himself upon that point of support with a sort of fury. This produced upon him the effect of the first step in a staircase leading back to life.
The point of support, thus encountered in the mire at the supreme moment, was the beginning of the other water-shed of the pavement, which had bent but had not given way, and which had curved under the water like a plank and in a single piece. Well built pavements form a vault and possess this sort of firmness. This fragment of the vaulting, partly submerged, but solid, was a veritable inclined plane, and, once on this plane, he was safe. Jean Valjean mounted this inclined plane and reached the other side of the quagmire.
As he emerged from the water, he came in contact with a stone and fell upon his knees. He reflected that this was but just, and he remained there for some time, with his soul absorbed in words addressed to God.
He rose to his feet, shivering, chilled, foul-smelling, bowed beneath the dying man whom he was dragging after him, all dripping with slime, and his soul filled with a strange light.
冉阿让面前是一块陷落的地。
当时这类塌陷在爱丽舍广场下面是经常发生的，这里的地下层对水利工程很不利，因为它的流动性极大，所以地下的建筑不够坚实。这种流动性的土壤较之圣乔治区的流沙还更不牢靠，流沙只在石块加混凝土筑成地基后才能加以克服；而流动性的土壤也不比殉教者区恶臭的有沼气的粘土层牢靠，这粘土稀薄到使殉教者区地下长廊的沟道只能用一条铸铁管来沟通。一八三六年，当局拆除并重建圣奥诺雷郊区下面旧的石砌沟渠，这正是冉阿让此刻所在之处，那时从爱丽舍广场直至塞纳河地下都是流沙，这一障碍使工程延长将近六个月，以致引起沿岸住户的强烈抗议，尤其是住大公馆和有马车的住户。工程不但艰巨，而且还非常危险，那时确是降了四个半月的雨，塞纳河的水位也三次升高。
冉阿让遇到的地陷是头天晚上的暴雨造成的。铺路石的下面是沙子，没有坚实的支撑，所以铺路石弯曲，形成了雨水的积聚。雨水既将铺路石浸透，于是坍塌相继而来，沟槽开裂后就陷入了泥沼。塌陷的地方究竟有多长？这无法说清。黑暗在这儿比任何地方都深厚，这是夜之洞穴中的一个泥坑。
冉阿让感到沟道在脚下陷落了，他踏进了泥浆。这里上面是水，下面是淤泥。但他还是得走过去。再转身走回头路已不可能了。现在马吕斯已濒危，冉阿让也已力竭。还有什么路可走呢？所以冉阿让仍继续前进。再说开始在洼地里走了几步，并不感到深，但越向前走，他的脚就越陷越深。不久淤泥深到腿的一半，而水则过了膝头。他一面走，一面用两臂把马吕斯尽量高举，超出水面。现在淤泥已到膝下，而水则到了腰际。他已无法再后退了，越陷越深。这淤泥的稠度可以承受一个人的重量，显然不能承受两个人的。如果马吕斯和冉阿让是单个走过去，则还有可能脱险。冉阿让仍继续往前走，举着这个垂死的人，这也可能是具尸体了。
水到了腋下，他感到自己在沉下去，他在这泥泞深处几乎无法活动。密度既支撑重量，但同时也是障碍。冉阿让一直举着马吕斯，因而就消耗大量体力向前走着，他在陷下去。现在他只剩下头部露出水面了，但两手仍高举着马吕斯。在有些洪水成灾的古代油画中，一个母亲就是这样举着她的孩子的。
他还在下沉，他仰起脸避水来保持呼吸。如果有人在这种黑暗里看见他，还以为这是个面具在暗中漂荡呢；他模糊地看见在他上面马吕斯倒垂的头和青灰色的面容；他拚命使了一下劲，把脚伸向前；他的脚触着了一个不知是什么的硬东西。
这是个支点。好险！再晚一点就不行了。
他竖起身来又弯下去，拚命在这个支点上站稳。他觉得自己好象踏上了生命阶梯上的第一级。
在污泥中危急万分时碰到的这一支点原来是沟道另一边的斜坡的开始，它弯而未断，在水下拱着，好象一整条地板，用石块砌得很好的建筑成一拱形而相当坚固。这一段沟槽，部分已陷入水中，但仍很结实，确是一个斜坡。一踏上这斜坡，人就得救了。冉阿让走上这平坦的斜坡，就走到了泥沼的另一边。
他走出水时，碰到一块石头就跪着跌倒了。他认为确应如此，他就这样待了一会儿，灵魂沉浸在向上帝祈祷的不知怎样的一种言语中。
他又站起来，颤抖着，感到僵冷，恶臭熏人，他弯腰去背这垂死的人，泥浆直淌，心里充满了奇异的光彩。