In 1929, Maisie Dobbs hangs up a sign announcing her investigation services. She becomes one of the first female detectives in London. Her life took a huge turn years ago when she started working for Lady Rowan Compton, an aristocrat who took notice of Maisie’s intelligence. Maisie's first case, which appears to be one involving infidelity, leads her to a home for veterans of World War I. This place ends up having an unexpected connection to her past.