Mr. Six, once a notorious gangster in the streets of Beijing, is now living a lonely life, isolated from his family and friends. One day he learns that his estranged son got into trouble with a powerful government official’s son and now is kidnapped due to debt. His attempt to resolve the matter using the old school gangsters’ rule miserably fails, and Mr. Six is humiliated. Now, he turns to his old friends, the retired gangs, to get his revenge.