The crooks in London know how it works. No one carries guns and no one resists the police. Then a new gang appears that go one better. They dress as police and steal from the crooks. This upset's the natural order of the police/criminal relationship and the police and the crooks join forces to catch the IPOs (Impersonating Police Officers), including an armored car robbery in which the police must help the gangs to set a trap.
露丝·斯雷特（布洛克饰）因暴力犯罪被判入狱，出狱后的她重新踏入社会，但自己的过去却不被原谅。面对来自她曾经称之为“家”的地方的无情评判，她获得救赎的唯一希望，就是找到当初被自己无奈丢下而疏远了的妹妹。
