In Italy in 1961 Eileen lives with her mother in their decadent family home. A lonely teenager, alienated from her peers and pressured by her mother to take care of the house, Eileen's only happiness comes from swimming, which she does for hours each day. When a journalist is impressed by her talent and convinces her to try and be the youngest person to cross the English Channel Eileen thinks it is her chance to escape and do what she loves most. But the harsh pressures of training clash dramatically with Eileen's naive passion and dreams.