The Long Shadow is a 1932 mystery detective novel by Anthony Gilbert, the pen name of British writer Lucy Beatrice Malleson. It is the seventh of ten novels in a series featuring her amateur detective and politician Scott Egerton, a precursor to her better known creation Arthur Crook.
Mademoiselle Robert had twenty five years earlier been a celebrated star on the Parisian stage before drifting in anonymity. Now she has been founded dead in a slum-like tenement in London, with a knife through her heart.