The series follows junior investigators Stefan and Rash, who are brought together by a link between two seemingly unrelated cases.

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.