The film follows Xu Lai, a former artist whose dreams were dashed when the responsibilities of life set in. With his life now revolving around his wife Cai Bo who is obsessed with having children, the quirks of his eccentric family and his mediocre, ordinary existence, Xu Lai hopes to reconnect with his first love Yang YIi on an upcoming vacation. However, his hopes are dashed when he finds himself wrapped up in a murder investigation that proves truth is often stranger than fiction.

Hong Kong nihilism. December 22, a street quarrel leads to the death of a gang leader’s son. Next day, he seeks revenge on his brother, a rival boss. He calls on Liu, a fixer, to import a hit man from the mainland. Lai Fu, a tough and youthful hick, arrives with a day pass. The cops, led by the morose Milo, hear about the killer; they open a full-scale Christmas Eve operation to find the warring brothers and Lai Fu. Lai Fu rescues a hooker, Dan Dan, from a sadist and asks her to help him find his way around Mongkok. By nightfall, Liu has double crossed Lai Fu, the brothers are hiding, the cops are everywhere, and Lai Fu and Dan Dan are on the run. Peace on earth, good will to all?