The plot concerns Maurice (Peter O'Toole), an elderly actor who finds himself increasingly attracted to his friend Ian's great-niece Jessie (Jodie Whittaker) while simultaneously finding himself in deteriorating health due to prostate cancer. Maurice's friend describes the great-niece as a trouble maker and a nuisance, but Maurice discovers that Jessie warms up to him when he starts interacting with her. He takes her to the National Gallery in London, England to view his favourite painting, the Rokeby Venus, by the Spanish artist Diego Velázquez.Jessie had expressed interest in modelling (Maurice initially mis-hears this as "yodelling") and Maurice arranges for Jessie to model nude for an art class. As a result of Jessie posing for the art class, and inspired by his favourite painting, Maurice decides to give Jessie the nickname "Venus". Maurice and Jessie develop a passive/aggressive relationship over the course of the film. Maurice is forward in terms of his attraction towards Jessie while Jessie occasionally indulges his whims to a limited extent, such as touching her hand and smelling her neck, but also retracts the indulgences when she feels that he has gone too far. The plot of the film revolves around the evolving friendship or relationship between the two characters. For Maurice, this appears to be the last attempt at something approaching a love life, as his prostate operation has left him impotent. For Jessie, it is less clear what she sees in Maurice. During the course of the film we see her do everything from exploiting him (trying to get him to buy her presents, trying to use his flat to have sex with a boy), taking care of him, flirting with him, and rejecting him sexually to engaging with him as a friend. During the course of the film we learn that she has been rejected by her mother and great-uncle for her promiscuous life style; it is implied that she is drawn to Maurice because he does not judge her as harshly as her family members have.The plot comes to a head when Jessie becomes involved with a boy. The two young lovers convince Maurice to take a walk so that they can have sex. Maurice initially obliges the request, but returns to kick them out of his flat. A scuffle ensues and Jessie knocks down Maurice, injuring him. Jessie leaves with the boy and apparently spends the night out partying with him at clubs, later returning to check on Maurice. When the paramedics arrive, Maurice claims he cannot remember who attacked him, much to Jessie's surprise. Then Maurice calls for "Venus" to take care of him. Jessie, remorseful, agrees to look after Maurice. Some time later, after Maurice has at least partly recovered, he takes Jessie to the seaside at Whitstable in Kent. As they sit down by the water Maurice says to Jessie "Now, we can really talk", and dies, leaning on her.