Darker(2014)

Darker is a crime thriller series that follows a mysterious vigilante killer targeting criminals who've escaped justice. After each murder, the killer leaves a death notification card—a chilling calling card that sparks public outcry and forces the authorities into action. The police assemble a special investigation team to hunt down the elusive murderer known only as "Darker." As the body count rises and the killer's motives become clearer, the line between justice and vengeance blurs. The series explores the cat-and-mouse game between law enforcement and a killer operating by their own moral code, raising questions about whether some criminals deserve a second chance at all.