This action-packed series draws to a dramatic close with DC Grace Harris raiding the blazing headquarters of a sinister religious cult called the Core. She goes in undercover posing as a new recruit, to infiltrate them (a dangerous task as the charismatic cult leader has a habit of chopping off people's fingers) to help catch members of the sect who have robbed a bank. But the case becomes very hot to handle when the cult leader sets the building on fire in a Waco-style siege. Harris's undercover work confirms Scott's worst fears – that the cult members are prepared to die for the charismatic leader. On a lighter note DI Scott hears his wife Stephanie has gone into labour just as the squad go into action.