Line of Duty

A brutal ambush on a police convoy leaves three officers dead and a protected witness fighting for his life.

Following the tragedy at the hospital, AC-12's Kate Fleming is planted undercover in Lindsay Denton's Missing Persons Unit. But Lindsay soon gathers compromising evidence against the anti-corruption team.

Lindsay is denied bail and finds herself targeted in prison. When she is subject to a violent attack, she tells Kate about a relationship with an executive police officer who may have had reasons to want her framed.

When Lindsay is given a special dispensation to leave prison to visit her dying mother, AC-12 realizes too late how much danger she may be in.

Lindsay fights for her life as details emerge about a vicious conspiracy involving corrupt police officers. With growing evidence of links between Deputy Chief Constable Dryden and the ambush, Hastings is under pressure to arrest his senior officer.

AC-12's investigation finally exposes a vicious criminal gang run from within the police department. But while Steve now appears convinced of Lindsay's innocence, Kate remains determined to prove that she had a role in the ambush.