After Cragen is accused of murder, the team works secretly around the clock to defend him. Meanwhile, when Amaro also becomes implicated in the scandal and his personal life falls apart, he refuses to go down quietly.

　　这一季开始，美丽的单身毒妈Nancy Botwin（玛丽·露易斯·帕克 Mary-Louise Parker 饰）正在自家的花园中，和大儿子Silas（亨特·帕瑞施 Hunter Parrish 饰）、小儿子Shane（亚历山大·古尔德 Alexander Gould 饰）、小叔子Andy （贾斯汀·柯克 Justin Kirk 饰）、好友Doug（凯文·尼龙 Kevin Nealon 饰）等享受家庭时光。突然，一个红点照在她的额头上。马上，Nancy被狙击枪击中倒地，众人慌作一团。小儿子Shane（亚历山大·古尔德 Alexander Gould 饰）并没有去念大学，而是考入了警察学校，并根据手头的资源查到了开枪射击Nancy的凶手——正是多年前Nancy交往过的那个去世缉毒警察的儿子。Shane是会暗中下手为母亲报仇呢，还是走法律程序把罪犯送上法庭？而Nancy会不会度过危险期？

　　Mac needs the help of a convicted arsonist recently released from prison to investigate the death of one of his FDNY firefighter friends.