The Prison Master Returns to the City

The king of the dark world returns to the most ordinary city. But he forgets that in this city... lies the childhood he lost. In the international mercenary world, no one dares to utter the name 'Prison Master' directly. He single-handedly destroyed three major mercenary groups, twelve countries' secret agents followed his lead, and he sat alone on the arbitration seat of global dark forces. All who broke the rules were personally 'imprisoned in hell' by him. But now, this man who terrifies the underworld, wearing a crumpled security guard uniform, squats at the entrance of 'Jiangcheng Jinxiu Huating' residential complex, frowning at a QR code— 'Why... why isn't it moving?' He can't use a phone, can't swipe a card, treats a dog-walking auntie as a 'surveillance target,' and dismantles debt collectors' tools with his bare hands as 'fortification obstacles.' Colleagues call him 'fool,' residents laugh at him as an idiot, but only he knows that the moment real danger arrives— what he pulls out isn't a phone, but a gun. A child 'deliberately sent away' returns with 108 'numbers' equally forgotten by the world. He seeks a person, a set of keys, an old house, and an answer to 'why me.' But when he finally pushes open that door, he discovers—the deepest secret of this city lies in the palm he clenched tightly at age six! — Description from novelcodex.org