1986: Adrien, Etienne, and Nina are ten years old when they meet at school and quickly become inseparable. They promise each other they will one day leave their provincial backwater, move to Paris, and never part. 2017: A car is pulled up from the bottom of the lake, a body inside. Virginie, a local journalist with an enigmatic past, reports on the case while also reflecting on the relationship between the three friends, who were unusually close when younger but now no longer speak. As Virginie moves closer to the surprising truth, relationships fray, and others are formed.

Spanning the years 1900 to 1977, The Covenant of Water is set in Kerala, on South India’s Malabar Coast, and follows three generations of a family that suffers a peculiar affliction: in every generation, at least one person dies by drowning—and in Kerala, water is everywhere. At the turn of the century, a twelve-year-old girl from Kerala’s long-existing Christian community, grieving the death of her father, is sent by boat to her wedding, where she will meet her forty-year-old husband for the first time.

Tuscany, 1944: As Allied troops advance and bombs fall around deserted villages, a young English soldier, Ulysses Temper, finds himself in the wine cellar of a deserted villa. There, he has a chance encounter with Evelyn Skinner, a middle-aged art historian who has come to Italy to salvage paintings from the ruins and recall long-forgotten memories of her own youth. In each other, Ulysses and Evelyn find a kindred spirit amidst the rubble of war-torn Italy, and set off on a course of events that will shape Ulysses's life for the next four decades.

William Waters grew up in a house silenced by tragedy, where his parents could hardly bear to look at him, much less love him—so when he meets the spirited and ambitious Julia Padavano in his freshman year of college, it’s as if the world has lit up around him. With Julia comes her family, as she and her three sisters are inseparable: Sylvie, the family’s dreamer, is happiest with her nose in a book; Cecelia is a free-spirited artist; and Emeline patiently takes care of them all.

In the spring of 2020, Lara’s three daughters return to the family's orchard in Northern Michigan. While picking cherries, they beg their mother to tell them the story of Peter Duke, a famous actor with whom she shared both a stage and a romance years before at a theater company called Tom Lake. As Lara recalls the past, her daughters examine their own lives and relationship with their mother, and are forced to reconsider the world and everything they thought they knew.