Une série d’attentats à la bombe se produit à Hong Kong, suscitant la peur parmi la population. L'ancien agent de déminage Poon Sing-fung (Andy Lau), tombé dans le coma à la suite d'une explosion, devient le principal suspect en raison de ses liens avec l'organisation criminelle Resurrection. Après son réveil, Poon est interrogé et emprisonné. Il s'évade pour découvrir la vérité et prouver son innocence. Sur sa route de fugitif, il demande l'aide à son ancien camarade d'armes, également démineur, Tung Cheuk-man (Lau Ching-wan). Cependant, les deux se querellent car Tung doit choisir entre la justice et l'amitié. Il décide de choisir cette-dernière et aide son ami. Au même moment, l'ex-petite amie de Poon, Pong Ling (Ni Ni), qui est maintenant inspectrice en chef de l'Unité de lutte contre le terrorisme, cherche désespérément à découvrir le coupable de la série d'explosions et persuade Poon d'entrer en contact avec le groupe Resurrection pour découvrir sa prochaine cible et prouver son innocence. Poon réalise qu'il est tout aussi difficile de dévoiler la vérité que de se débarrasser d'explosifs.
The movie begins by Jackie Chan telling the story of the Old Summer Palace and its looting and destruction by British and French soldiers in the Second Opium War. Among the treasures stolen are twelve bronze heads of the animals of the Chinese zodiac.
En 1959, Ip Man vit à Hong Kong avec sa femme et son deuxième fils. Vivant de ses cours de wing chun, il va se retrouver à protéger l'école de son fils d'un promoteur américain prêt à tout pour acheter le terrain. Il va alors voir apparaître un rival, Cheung Tin-chi, aussi doué en wing chun mais très pauvre.
Ken (Chow Yun-fat), surnommé « Main magique », vit maintenant une vie luxueuse loin du stress du monde du jeu et des inévitables implications avec les criminels qu’il entraîne. Son protégé, Vincent (Shawn Yue), travaille pour Interpol dans le but de faire tomber l'organisation criminelle DOA, et sa demande d’aide à son maître est systématique repoussée par Ken. Ce n’est que lorsque ce-dernier est impliqué dans une fusillade qui le met en danger, lui et ses amis, qu’il accepte à contrecœur d’aider Interpol et que lui et Vincent commencent à remonter la trace d'un ex-comptable de DOA, Mark (Nick Cheung). Seulement , celui-ci a détourné 15 milliards $ de ses anciens employeurs, s'attirant contre lui toute la puissance du monde criminel.
La police de Hong Kong assiste aux obsèques des deux surintendants tués lors du film précédent. Peu de temps après, le commissaire Sean Lau (Aaron Kwok) reçoit un appel de l'un des responsables du vol du fourgon de police qui lui dit que sa femme a été enlevée et qu'elle sera échangée contre Joe Lee (Eddie Peng). Lau outrepasse la procédure habituelle pour transférer Joe hors de prison et le ravisseur lui ordonne de l'amener à une station de métro. Sur place, Joe réussit à s’échapper grâce à ses complices, dont l’un déclenche une bombe. Les criminels libèrent dans le même temps la femme de Lau dans la station.
In Shanghai during the 1930s, Sing and his friend Bone attempt to join the Deadly Axe Gang which ruthlessly control the city under leadership of Brother Sum. Sing seeks to restore his confidence after being humiliated as a young boy while trying to protect a mute girl from bullies, due to the failure of the Buddhist Palm method he had learned from a pamphlet he bought from beggar. Sing and Bone attempt to intimidate the residents of Pig Sty Alley but are chased off by its Landlady. Hearing of this, Sum orders Sing and Bone captured, while sending the Gang to reassert its authority from the humiliation. Three of the tenants, Coolie, Fairy, and Donut, are revealed as martial arts masters and defeat more than fifty of the Gang. Fearing retribution, the Landlady evicts the three, but they meet a pair of hired assassins using a magical guqin to launch invisible blades. Coolie is beheaded, and Fairy and Donut are mortally wounded before the Landlady and her husband the Landlord reveal that they too are martial arts masters, having gone into self-exile after the death of their son. The two defeat the assassins but Fairy and Donut die from their wounds. The Landlords temporarily evacuate the other tenants for their safety.
En 2055 une météorite, qui porte une semence extraterrestre étrangère à croissance rapide appelée « Pandora », s'écrase sur une Terre stérile ravagée par la pollution et le réchauffement climatique. « Pandora » purifie la planète mais tue tout sur son passage. Pour protéger les citoyens de Hong Kong, des unités blindées lourdes de la ville, équipées de la carte génétique de la plante, tentent de détruire « Pandora » sans succès et découvrent un complot.
In early 20th century Shanghai, Chen Zhen returns to Jingwu School to marry his fiancée. However, tragic news awaits him: his master Huo Yuanjia has died, apparently from illness. Chen is deeply saddened and traumatised by the sudden demise of his teacher. During the funeral, people from a Japanese dojo in Hongkou District arrive to taunt the Jingwu students. Wu En, the Japanese dojo's grandmaster Hiroshi Suzuki's translator and adviser, taunts Chen by slapping him on the cheek several times, and dares him to fight him. Then the Japanese students, along with Wu, leave. Shortly thereafter, Chen goes to the Hongkou dojo alone to engage in a fight. Chen defeats all of them, including the students' master.
In AD 859, as the Tang Dynasty declines, a number of rebel groups are established, the largest of which is the House of Flying Daggers, based in Fengtian. Its members steal from the rich and give to the poor, gaining the support of the locals. Two police officers, Leo (Andy Lau) and Jin (Takeshi Kaneshiro), are ordered to kill the leader of the group within ten days.
Kit is a Hong Kong undercover cop who becomes a drug addict to infiltrate a crime syndicate which has been kidnapping people and sending them to Thailand, where the victims are killed and have their organs sold in the black market. The mastermind behind the syndicate, Mr Hung, has a rare heart condition and needs to undergo a heart transplant to prolong his life. Hung's younger brother is the ideal donor for a heart.
En 1963, un immigrant clandestin chinois (Donnie Yen) arrive dans la colonie britannique corrompue de Hong Kong. Sous le nom de « Ho l’estropié », il devient petit à petit un puissant baron de la drogue grâce à sa ruse et sa cruauté. Il est aidé dans son ascension par Lee Rock (Andy Lau), un inspecteur de police corrompu, pour affronter les gangs rivaux.
Illegal immigrant Howard (Cheung) arrives in Hong Kong and joins the underground world - the intersection between the Triads and the corrupt elements of the police force.
Ma Hon Keung (Jackie Chan), a Hong Kong cop comes to New York to attend the wedding of his Uncle Bill (Bill Tung) who introduces his new, African-American wife Whitney to him down at his supermarket, which he owns and has sold to Elaine (Anita Mui). Uncle Bill's friend, Steven Lo (Jamie Luk), loans him a vintage automobile for the wedding. Later that night, a street gang starts a motorcycle race near Uncle Bill's apartment. They are about to run over his friend's car until Keung jumps down and stops them. He soon starts a rivalry with the street gang when he drives them away from the supermarket that they were robbing and vandalizing. This starts a series of brawls in which the bikers try to corner Keung and finish him off. When a member of the street gang named Angelo (Garvin Cross) gets involved in an illegal diamond deal gone bad and steals the diamonds, the small-time gangsters become the victims of a much larger and more effective criminal syndicate led by White Tiger (Kris Lord). While running away with the diamonds, Angelo leaves them in a cushion, which is unknowingly used by Keung for the wheelchair of a disabled Chinese American boy named Danny (Morgan Lam), who is raised by his elder sister Nancy (Françoise Yip), a lingerie model/dancer who works in a seedy bar and is an associate/girlfriend of the bikers. Keung befriends Nancy and advises her to stay away from crime. When the gangsters see this, they chase Keung and Nancy. After failing to confront Keung, the bikers turn up at Elaine's supermarket and start vandalizing it, during which two of Angelo's men are captured by White Tiger's men, who turn up at the supermarket in search of Angelo. Angelo's colleagues are unaware of his diamond heist and one is executed in a tree-shredder; his remains are given back to the other gangster to show to his friends as a warning to return the multimillion-dollar goods. In the meantime, Keung and Nancy go to the bikers' shed after the latest supermarket attack, and Keung defeats them in another brawl, at which point the shredded remains are brought back.