Shen Mo, a computer repairman with severe social anxiety, stumbles into the underworld while trying to pay off debts and is mistaken for a cold-blooded "cleaner." Barely able to string a sentence together, his clumsy mishaps—a knife slipping from his trembling hand, knocking over a trash can—are imagined by his subordinates as the moves of a peerless master. To protect Wen Wan, a café owner whose father has gone missing, Shen Mo plays along, using his tech skills to maneuver between two rival factions, expose a mole, and crack a money-laundering case. In the end, he finds himself amid the gang's transformation and gains love along the way. This is a hilarious, heartwarming story of a "socially anxious loser" who blunders and gets overimagined into a "legend."