In an Edinburgh cellar, two gunshots ring out. Across town, Max McCall is released from prison. These two events gradually converge as Max tries to rebuild his life, while new arrival Erin is trying to save hers.
Catherine在一个抽干的蓄水池里发现了一名黑帮谋杀受害者的遗体，这触发了一系列的连锁事件，不知不觉间将她直接引向了Tommy Lee Royce。 Catherine的外孙Ryan现在16岁了，仍与她住在一起，但他对于想跟外祖母拒绝承认是他父亲的那个人建立何种关系，有着自己的想法。仍在与镇上似乎永无止境的毒品问题以及供应者作斗争，Catherine也即将迎来退休。
