As World War I engulfs Europe, a special task force is formed in the affluent Mayfair district to tackle the city’s thorniest crimes against women. When the bobbies and Scotland Yard come up short, there’s only one telephone number to dial: Mayfair 100. An aristocrat has been murdered, and his wife, a witness and possible suspect, will only talk to a woman. With the blessing of London’s Chief Commissioner, Chief Inspector Beech, a young man invalided out of the war, assembles a crew of sharp, intrepid and well-educated women to investigate. But to get at the truth, Beech, Victoria, Caroline, Rigsby and Tollman will venture into the the city’s seedy underbelly, a world where murder is only the first in a litany of evils.