The Clerk They Mocked Was a Legendary Spy

DramaBox synopsis

He was the CIA's only agent named Zero. Then he became a school social worker—mocked, ignored, called a coward. When the mafia kidnapped his daughter, they thought they were untouchable. They didn't know who they'd provoked. One man. One gun. An entire crime family in his path. But the worst is yet to come—because someone far more dangerous is already hunting him.