It was at the bottom of the Esplanade des Invalides she saw Maud. The rain was still tumbling from the sky and the wind was strong, but everywhere the Quais were full of people. The horse-drawn omnibuses had their upper decks full. Men and women were half-standing or lifting their children in their arms so the little ones could see the yellowish tumbling masses of water spreading out, hiding the streets, turning the lamp posts into isolated floating globes of light where no one could reach them to shut off the gas. Working men carried ladies on their backs across the huge ponds that appeared in the middle of fashionable boulevards. Soldiers and engineers threw up raised wooden walkways around the edges of the sunken streets and the bemused and excited holiday crowd shuffled along them, their feet making the planks shake and lift.

Maud was staring into the crowd on one of these walkways. Yvette called her name but she didn’t move. As Yvette watched, she calmly furled her umbrella and lifted her veil. There was a shout opposite and the crowd shifted. Yvette looked across and with a sick lurch recognised Morel as he turned against the flow of people on the wooden walkway and begin to try and push against them. He had seen her. My God, she had shown herself! The crowd protested and a man pushed hard against him. One of the women in the crowd stumbled and was saved by her friend as she cried out.

Yvette watched, horrified, as Morel leaped down into the dirty water and begin to wade heavily across the lake towards Maud. The crowd jeered and shouted at him. Yvette twisted around to try and see Maud again but the flowing crowd had hidden her.

A scream, more urgent and afraid, followed by shouts for help to her right. For a moment more Yvette searched for Maud, then she looked over her shoulder. An omnibus, its horses straining and scrabbling on the flooded cobbles, was tilted crazily in the road.

‘Sinkhole!’ a boy next to Yvette shouted with delight. ‘The road is falling in!’

Men began to gather at the front of the omnibus, pulling with the horses on the shafts, while at the rear the crowd held out its arms to receive the passengers clambering from the footplate on to solid ground. The surface water on the road flowed towards the hole.

Yvette hitched up her skirts above her ankles and pushed her way to the front of the crowd. The last of the passengers were jumping and scrambling from the footplate to the edge of the hole, the crowd grabbing on to their arms and hauling them roughly to safety. Yvette looked down at the ripped and snaggled edge of the paving. The water that fell through it from the road dropped some ten feet into almost complete darkness. A subway tunnel or sewer that ran like an artery under the skin of the city, now obscenely exposed to the air. You could hear the angry rush of the water below echoing against the stone.

A woman in a long black coat, her hat topped with soaking ostrich plumes, trembled on the step.

‘Jump!’

A man held out his arms but she clung to the pole and shook her head a little. A man and two girls pushed past her to leap and scramble to solid ground. Then one of the girls, a little grisette in a short skirt, turned and saw the older woman trembling on the brink. Without any sign of doubt or fear, she stepped back over the blackness below again.

‘See, Madame! See, it is an easy jump! Please?’

The woman looked at her with desperate eyes.

‘Look at me, Madame. Look only at me. I’m going to help you let go now and then we shall step off together, yes? Just like every day when they set us down on the Champs. Just like every day.’

The girl slid her hand up the pole, working her fingers under the grip of the older woman and pulled her hand free. ‘Here we go!’ Still smiling, still looking at the older woman, she half-pushed, half-pulled her into the air. The crowd all reached for them and caught them.

‘Cut the horses free!’

The bus lurched backwards, its back right wheel spinning in the hole, wood cracked and split and all the packages and belongings of its riders, the forgotten or abandoned bags and hats, umbrellas and paper packages, slid out and tumbled into the fiercely churning waters below.

Yvette turned towards where she had seen Maud. Morel was standing there, up to his knees in water. He looked in her direction and stared. A woman approached him, and with a lurch Yvette recognised her from the picture tacked on the wall in Valadon’s place. She took his arm and bent forward, speaking to him softly, urgently. Yvette found she could not move. Eventually Morel turned towards the woman and started to say something, then took off his round hat and ran his hand through his hair.

A small crowd had gathered around the foundered bus and were lifting their cameras to catch its image with the domes of Les Invalides in the distance. A near tragedy became a postcard as she watched. A few feet away the older woman had her arms wrapped round the little grisette while the girl smiled and patted her on the back. Yvette shook herself. She must find Maud. By the time she turned back round again, Morel and Sylvie had disappeared.