It is 1936. Undercook Joan Hart and lady's maid Verity Hunter are back in London after a long stay in the country. The capital is fraught and unsettled. Protests and riots are taking place regularly, fascism is on the rise and trouble in Europe is brewing, but the girls are still thrilled to be back in the Big Smoke, ready for some fun and frivolity. That is, until an old friend of Verity's contacts the servant sleuths, asking for help. Maidservant Theda Samuels was the only one in the house when tycoon Sir Jacob MacMullen was killed, and things are looking very black for her . . . unless Joan, Verity and their old ally Inspector Marks might be able to help?