There is Colin. And there is Chloé.
There is Chick. And there is Alise.
There is Nicolas with his magical piano-cocktail.
There is the philosopher Jean-Sol Partre, and the little grey mouse, and there is post WWII Paris, and there is jazz.
And then there is the ominous waterlily, growing in Chloé’s lung.
The action takes place in Paris in the aftermath of WWII. There is a new sense of freedom that pervades the city: everything is possible, no matter how surreal. Parisian youth are bursting with joie de vivre, they want to party, to listen to jazz, to fall in love.
Young and wealthy Colin is no exception to this (ʽAh! Comme la vie serait triste si l'on ne pouvait pas chanter!ʼ) He has dinner with his friend Chick, during which his butler Nicolas shows off his contraption the piano-cocktail, which prepares cocktails inspired by the music played. During dinner he confides to Chick that he has dreamt of a girl he wants to meet. Chick wants to fall in love too: he has met Alise, Nicolas’ niece, at a conference by Jean-Sol Partre (a pun on the notorious philosopher).
The next day at the skate rink, Chick and Colin meet Alise and Isis, who invites them to her dog’s birthday celebration (ʽNe vous mariez pas, les filles!ʼ) Alise makes clear to Chick that she intends not to marry him because he is too obsessed with Partre. At the party Colin meets Chloé, whom he recognises as the girl of his dream. Colin and Chloé escape the party to walk through the city, and then take a ride on a pink cloud that shields them from being seen from other people. They fall in love (ʽChloé, vos lèvres sont doucesʼ).
Chloé, Alise and Isis prepare for the wedding; everyone is bursting with joy and love.
This happiness, however, won’t last long.
While Colin and Chloé leave are on their honeymoon, Chloé has a vision of monsters, dirt and smoke. Back in Paris, she complains about a pain in her chest. The house starts behaving bizarrely, too: the tiles have trouble breathing and the walls seem to have started shrinking. The doctor delivers a fatal diagnosis: Chloé has a waterlily growing in her lung. The only possible cure is to constantly surround the lily with prettier flowers so that she won’t grow bigger. At Chloe’s sickbed, Colin consoles her by reading a novel about Tristan and Isolde (ʽEt Iseut s'écrie: Hélasʼ).
To pay for the mounting flower bills, Colin ends up working at the military factory, where he grows weapons from seeds. Meanwhile, Chloé is not getting better. Alise enters the flower-packed room and informs Colin that Chick has spent all his money on Jean-Sol Partre books, and that he wants to leave her.
Policemen go to Chick’s house to confiscate his property; a fight ensues, in which Chick dies defending his books. Desperate Alise sets fire to the bookshops showcasing books by Jean-Sol Partre, and Paris is on fire.
Chloé is dead. Colin is in despair. He discusses with Jesus nailed to the cross the futility of all these deaths (ʽAgnus Deiʼ). The house mouse wants out too and ask the cat for help, but the cat is unconvinced (ʽVraiment, ça ne m'intéresse pas énormémentʼ). A blind girl walking down the streets steps on the cat’s tail: the cat shuts its mouth around the mouse’s head.