Six years after a sinister drugs trial in India goes horribly wrong, a young teacher is found dead. Two investigators - trainee Detective Constable Arrash 'Rash' Sayyad and junior Serious Fraud Office investigator Stefan Kowolski - are separately drawn in, investigating different strands of the same case under the watch of their respective bosses, DS Derek Sands and Eleanor Davies. As a war begins to rage between two major pharmaceutical companies and with two hit-women on their trail, Rash and Stefan's paths unexpectedly cross, forcing them to join together to uncover the truth.

Set in 1920s London, a brutal and bloodthirsty murder has stained the plush carpets of a handsome London townhouse. The victim is the glamorous and rich Emily French. All the evidence points to Leonard Vole, a young chancer to whom the heiress left her vast fortune and who ruthlessly took her life. At least, this is the story that Emily's dedicated housekeeper Janet McIntyre stands by in court. Leonard however, is adamant that his partner, the enigmatic chorus girl Romaine, can prove his innocence. Tasked with representing Leonard is his solicitor John Mayhew and King's Counsel, Sir Charles Carter KC.