In 1760, in Brittany, France, the talented young female painter Marianne (Noémie Merlant) received a commission to complete a portrait of the rich lady Héloïse (Adèle Haenel) before her wedding without her knowledge. The two depended on each other on an isolated island. During the day, the female painter secretly observed the lady's every move, and only started to paint at night. Under the close contact between the two, even in an era full of etiquette and restraint, they gradually developed taboos and ambiguous feelings. As the wedding day approached, their love became more and more intense...