Set in the present day, "The Iron Lady" spends three days with Margaret Thatcher, now in her 80s, her world constrained by her security needs and the debilities of age. Living in a world of female caretakers, she is consoled by conversations with her husband, Denis, who has passed on but whose imagined presence provides companionship. Making yet another of the many tough decisions of her turbulent life, she decides, finally, to let go of his clothes and possessions. This destabilizing moment triggers alarm, and memories of her embattled past begin to ambush her. As Margaret is hurtled from her wartime childhood as a grocer's daughter onto the roller coaster of her political life, she considers the great personal cost her convictions have exacted on the nation, her detractors, her supporters, her family, and finally herself.