Mr Herbert Wrayson, a 32-year-old bachelor, witnesses the murder of his neighbour Mr Morris Barnes. Unbeknownst to him, he is the estranged daughter of Colonel Fitzmaurice, a kindly soul who lives to help others. The trail of witnesses, accomplices, and potential inheritors grows longer and more complicated, while Wrayson falls in love with Louise, the companion of the Baroness de Sturm. A trip to France brings further mystery, as Louise is living in a highly guarded Chateau with Madame de Malbain and is surrounded by spies. Oppenheim's novel conveys the life of pre-War London, the role of the famous Alhambra music hall, and the manners of the upper class.