November 1965. American actress Iolanthe Green has become the toast of the West End, bringing a sprinkling of glamour to the scuffed boards of Soho's Galaxy Theatre. But one evening Iolanthe walks through the stage door, out into the cold London night, and vanishes. As the case grows colder, only Anna Treadway, Iolanthe's dresser at the Galaxy, still cares. A disparate band of London émigrés joins Anna in her quest, an odyssey that leads them into a netherworld of jazz clubs, backstreet doctors, police brutality, and seaside ghost towns.