When British hat manufacturer Christopher Brooke is arrested under Regulation 18B in June 1940 a slow process of personal disintegration begins. Taking us into the pre-war political era of Ishiguro's Remains of the Day, Mad Hatter delves into the lives of Britons, tracking them through a darkening time. Irish farm girl, Mary Byrne, arrives in England in July 1940 to work as housekeeper for Cynthia Brooke and her three children, bonding with the family. When Mary is shockingly expelled from the house upon Christopher's release, her narration continues through the mouth of 15-month-old Katie. Mad Hatter charts the slow unravelling of a marriage as the story of the Brooke family moves inexorably to a tragic conclusion.