Their story is that of a dazzling conquest of the planet: flowers now represent 90% of plant species. An unchallenged domination that has intrigued scientists for centuries. According to Charles Darwin, "the rapid development of flowering plants is an abominable mystery" on which a new generation of scientists is studying: paleontologists, biologists, geneticists are tracking down the slightest clue all over the world. From the African deserts to the forests of New Caledonia, via the summits of the Alps, they are making astonishing discoveries. What is the place of flowers in the tree of life? When did they appear on Earth?