Nora, an editor at a London publishing house, lives alone and keeps herself tightly closed off. Her new neighbour Finn is a fox spirit who feeds on intense human emotion, and at first he steals her shame and anxiety while repeatedly overstepping into her life. Losing control, he reads a painful memory she had buried, and she throws him out.
The two then establish a rule: nothing may be taken without consent. As Finn honours it, he discovers that joy and warmth, freely given, nourish him just as well. With Nora, pet-shop owner Rosa, and neighbour Mrs. Hart, he learns to apologise, hold a job, and stand on his own, until he publishes his own picture book. Nora, in turn, learns to say a complete "no," wins lead credit on a project, conquers her fear of public speaking, and finishes her own book.
In the end, Finn moves into a flat three minutes away and becomes her family, while Nora finally confesses to Oliver, the café owner, and the two become a couple.