Il y a cinq ans, Lau (Louis Koo) a été condamné pour le meurtre d'un important propriétaire foncier lors d'un accident de voiture. À cette époque, il travaillait comme chauffeur pour To (Kenneth Tsang), un magnat de la campagne.
Whilst working for the CIA, Chan Ka-kui (Jackie Chan) is assigned to follow leads of a nuclear smuggling case. He follows a woman named Natasha to Ukraine, when he realizes that she had been hiding vital information, Ka-kui calls for backup and she is later arrested. However, Natasha's partner is an unknown man, who turns out to be Jackson Tsui (Jackson Liu), a Chinese American nuclear scientist with CIA links, suspected of stealing a nuclear warhead. Ka-kui follows Tsui to a restricted area, and after a trap set by Tsui, the CIA agents together with Ukrainian authorities engage in battle. Ka-kui finds a briefcase which contained evidence from Tsui, but as he is chased by unknown forces, Ka-kui loses the briefcase as he falls into frozen waters.
In year 689 of the Tang Dynasty, Wu Zetian is about to be crowned the first Empress in China despite opposition from Tang officials. To mark this occasion, she has a colossal Buddha figure built overlooking her palace. However, an official inspecting the Buddha's progress mysteriously erupts into flames. Penal officer Pei Donglai and his superior investigate and interrogates the supervising builder, a man named Shatuo, who was formerly imprisoned after he took part in a rebellion eight years ago. They find nothing, however, and Pei's superior dies soon after in the same manner as the official.
Chow Ti is a poor construction worker. He lives in a partially demolished house with his nine-year-old son, Dicky. Chow is eager to save money so he can continue sending his son to private school. However, Dicky is often bullied by other children and his teacher at school.
Deux policiers (Lau Ching-wan et Nick Cheung) et un autre infiltré (Louis Koo) luttent contre un puissant baron de la drogue thaïlandais surnommé le « Bouddha à huit têtes » et doté d'une véritable armée de mercenaires.
Sous le règne du roi Zhou (Tony Leung Ka-Fai), un fonctionnaire entre dans sa chambre, et est dévoré par les queues monstrueuses de Daji (Fan Bingbing), sa concubine. En dehors de leur ville, plusieurs guerriers dans un wagon métallique de discuter de leurs stratégies pour libérer les gens invisibles et leur chef, lorsque Jiang Ziya (Jet Li) semble leur. Il leur dit que, lorsque le roi Zhou était plus jeune, il se laissa devenir possédé par le Dragon Noir pour sa quête du pouvoir.
Sing (Stephen Chow) is a master of Shaolin kung fu, whose goal in life is to promote the spiritual and practical benefits of the art to modern society. He experiments with various methods, but none bear positive results. He then meets "Golden Leg" Fung (Ng Man-tat), a legendary Hong Kong soccer star in his day, who is now walking with a limp, following the treachery of a former teammate Hung (Patrick Tse), now a rich businessman.
Bu (Shu Qi) is a beautiful young girl from a small Taiwanese fishing village who discovers a romantic message in a bottle. She heads for Hong Kong to find its writer, only to learn that it was in fact written by Albert (Tony Leung Chiu Wai), a lonely gay man. She, however, meets the wealthy recycling company owner, C.N. (Jackie Chan) who falls in love with her; but the plot is soon thickened by rival businessmen, hired goons, and Bu's confused would be boyfriend.
Forced to leave service after turning blind, former detective Johnston Chong See Tun (Andy Lau) ekes out his living by solving cold cases for police rewards. During a case involving the search for the culprit who throws acid off roofs, he meets an attractive hit team inspector Goldie Ho Ka Tung (Sammi Cheng). When Ho notices Johnston's impressive investigative mind despite lack of vision, she enlists his help in a personal case she is unable to solve on her own. The two work together to solve the case as well as other cold cases.
Continuing from where the first film ended, Wing Chun master Ip Man and his family move to Hong Kong in the early 1950s after their escape from Foshan. There, Ip desires to open a school to propagate his art, as well as make a living during the difficult times, but he has difficulty attracting students due to his lack of reputation in the city. One day, a young man named Wong Leung appears and promptly challenges Ip to a fight, but is easily defeated. Wong leaves humiliated, only to return with some friends to gang up on him. Ip beats them as well. Stunned and impressed by his skills, Wong and his friends become Ip's first students, bringing more disciples to help the school thrive.
Peace-keeping immortals living in clans inhabit a mythical mountain range called Zu, which exists between Heaven and Earth. A demon called Insomnia desires to rule Zu and the world below; it begins wiping out the various clans. In the Kunlun Mountains, Dawn sends away her apprentice, King Sky, because she believes that their emotional attachment hinders their progress. She gives him her weapon, the Moon Orb, to help him train; he is to return only after attaining a higher level. If she cannot be found, the Moon Orb will find her. Moments after they part, Insomnia attacks Dawn and disintegrates her.
One day in 1999 when his two-year-old son Lei Da went missing, Anhui farmer Lei Zekuan (Lau) begins his fifteen-year-long journey of hardship searching for his lost son. On his way he meets Zeng Shuai, a young car mechanic who was abducted as a child himself and is also searching for his parents.
Eddie Yang (Jackie Chan) is a Hong Kong police officer cooperating with Interpol in the capture of a crime lord named AJ "Snakehead" Staul (Julian Sands). Snakehead procures an ancient book from a Chinese bookstore keeper, which tells the story of a boy being chosen every thousand years to bind the two halves of a legendary medallion. In Hong Kong, Eddie and Interpol agent Arthur Watson (Lee Evans) lead a raid to capture Snakehead and his men, who are about to kidnap the boy, named Jai (Alex Bao). Eddie and the agents fight off Snakehead's men, infiltrating the temple containing Jai. Jai is saved but Snakehead eludes them. Two weeks later Snakehead captures Jai aboard a cargo boat in Hong Kong. Eddie and a team of Hong Kong police engage and defeat several of Snakehead's men, but Snakehead escapes with Jai to Dublin, Ireland.