The details of undercover police officers are deleted from a police database and a senior officer is left struggling to know who are the undercover officers and who are the criminals.

After the hot-tempered police detective Fei messes up yet another operation, he is transferred to a fictional department that houses all the useless staff the force couldn’t sack. There he finds a new enemy in the mild-mannered desk officer Johnny, who loathes Fei’s disregard for discipline. But when Fei’s father and Johnny’s mother coincidentally become an item, the new brothers must somehow learn to cohabit under the same roof.