When her detective husband Ryan is murdered, PC Jo Gillespie is expected to leave it to her colleagues in the force to find his killer, but finds herself losing trust in them and goes behind their backs to track down the killer herself. However, her investigation places her and her children in jeopardy.

A suspect is taken into custody for Ryan's murder, but Jo is not convinced the police have the guilty party. She continues to investigate her husband's undercover work, discovering dark secrets relating to both his colleagues and the criminals they were pursuing, and finally coming to a disturbing revelation about the man she married.

When her detective husband Ryan is murdered, PC Jo Gillespie is shocked to discover he was working undercover. Reeling from a secret that strikes at the heart of her family, Jo decides to put the needs of her children first.