Cover Her Face

Scotland Yard's Adam Dalgliesh is called in to investigate the murder of a drug dealer found strangled in the basement of a respectable London book club. His key witness in the case turns out to beautiful young single mother, Sally Jupp, on a day visit to London to "introduce" her eight-week-old son to former employers and co-workers at the book club.
The investigation switches back and forth between the urban drug scene, where one detective has already been killed, and the country residence of the socially conscious Maxie family, where the recently employed young woman has made more enemies than friends.
As mysterious deaths pile up, Dalgliesh is immersed in a sea of suspects, aggressive, evasive answers and deeply hidden motives. (official distributor synopsis)