格蕾丝、安妮和汤米正在迅速成长为警察，但没有什么能让他们为每天面临的混乱做好准备。麦金太尔犯罪团伙垮台已经一年了，真空被敌对帮派填补，他们都在争夺统治地位。警员肖恩·布拉德利被征召来帮忙，但他的动机尚不清楚。汤米被情报警察的世界危险地诱惑，而格蕾丝努力处理她儿子的缺席，以及对同事史蒂夫日益增长的感情。当一个年轻的忠诚者威胁要接管这座城市时，警官们面临着一场主要的帮派争斗——最终以暴力和毁灭性的对抗告终。

Grace, Annie and Tommy are growing up fast as police officers, but nothing can prepare them for the turmoil they face every day. It’s a year since the fall of the McIntyre crime gang and the vacuum has been filled by rival gangs, all competing for dominance. Constable Shane Bradley is drafted in to help, but his motivations are unclear. Tommy is dangerously seduced by the world of intelligence policing, while Grace struggles to deal with her son’s absence, and growing feelings for fellow officer Stevie. As a young loyalist threatens to take over the city, the officers face a major gangland feud – culminating in a violent and devastating confrontation.