It has been years since the whole family was all together. Now the Malegarde family is gathering for Paul, Linden's father's 70th birthday. Each member of the Malegarde family is on edge, holding their breath, afraid one wrong move will shatter their delicate harmony. Paul, the quiet patriarch, an internationally-renowned arborist obsessed with his trees and little else, has always had an uneasy relationship with his son. Lauren, his American wife, is determined that the weekend celebration will be a success. Tilia, Linden's blunt older sister, projects an air of false fulfillment. And Lindon himself, the youngest, uncomfortable in his own skin, never quite at home no matter where he lives, an American in France and a Frenchman in the U.S., still fears that, despite his hard-won success as a celebrated photographer, he will always be a disappointment to his parents. Their hidden fears and secrets slowly unravel as the City of Light undergoes a stunning natural disaster, and the Seine bursts its banks and floods the city. All members of the family will have to fight to keep their unity against tragic circumstances.