Modern Interiors rummages around in the back rooms and passageways of the family. When her husband dies, Philippa Finemore, formerly a pillar of the Establishment, is determined to broaden her life. She sells the family mansion, acquires a lover and new friends, and devises new plans for the family money. Her adult children, rather than welcoming her new direction, are unrestrained in their condemnation of what they perceive as gross irresponsibility and personal betrayal.