It's 1952 in Britain, and things seem to be looking up for Harriet Wallis: Her husband has a job with an important firm; the children are settling in with the new nanny; and the whole grim, ghastly past is gone. But when Coronation Day arrives, as family and friends gather at her home to drink champagne and watch the historic event on the brand-new television set, Harriet Wallis will pump six bullets into her husband's body, setting herself on the path to becoming second-last woman in England to be hanged.