前刑警队长落网，龙宇集团势力重组，多年前令全市女孩恐惧的碎尸案真凶逐渐浮出水面，十二年前，是什么，让那个充满正义感的警界奇才，变身成为冷酷的杀手。十二年后，是什么样的因果，让新一代的darker，无法逃避自己的宿命。Darker对生父死亡真相调查的不懈努力，一三零人质劫持案——那被警界传奇刻意隐瞒多年的真相得以揭晓，老师的“失误”，能否使Darker放弃杀戮，少女的柔情，能否使他得到救赎。

The special task force is adrift after their epic loss to Darker, the mastermind behind series of high profile vigilante killings. With their captain on the run for murder and them no closer to catching Darker, the team switches gear and investigates a decades-old hostage case. In those dusty old files, they discover Darker's real identity and a possible police coverup, but establishing the wrongdoer and the aggrieved party proven more difficult than it seemed. The team must determine the true culprit before Darker does, lest he kills his way through the suspect list.