On a bitterly cold London evening, schoolteacher Kyra Hollis (Carey Mulligan) receives an unexpected visit from her one-time boss and former lover, Tom Sergeant (Bill Nighy), a successful and charismatic restaurateur. When Tom’s wife discovered their relationship, Kyra had walked out – on Tom, and their work together at Tom’s restaurant – for a teaching job at a money-starved state school. Now, years later, Tom’s wife is dead; burdened with conflicting emotions – guilt, grief, longing – he has returned to settle unfinished business. But Kyra has built a new life for herself as a dedicated teacher for the under-served youth of the East End, and Tom’s arrival knocks her out of her carefully constructed equanimity. As the evening progresses, the two attempt to rekindle their once passionate relationship, only to find themselves locked in a dangerous battle of opposing ideologies and mutual desires.