In 1958, in the French Alps, a young servant, Anna Jurin, arrives at Saint Ange Orphanage to work with Helena while the orphans are moved to new families. Anna, who is secretly pregnant, meets the last orphan, Judith, left behind because of her mental problems, and they become closer when Anna finds that Judith can also hear voices and footsteps of children. Anna investigate the place trying to disclose the secret about the invisible children.