In the 1980s, Yin-Gor To, a passionate action director, choreographs a miscalculated jump that leaves a stuntman in his crew paralyzed. After the accident, he leaves the film industry and becomes a dit da practitioner.
In modern times, Wai Gor, [Philip Ng], is approached by an acquainted director Cho at a martial arts club dinner. Cho wants to film his swan song, envisioned as a 1980s-style action film, and suggests that Lee join the project as the action director. Lee reluctantly agrees out of friendship. Cho's film features Wai, a now international action star and former Lee's crew member, who despises Lee's ambitious and unsafe working methods. After some persuasion, Wai agrees to Lee's participation but insists on using his crew for the non-dangerous stunts. Lee then invites Long, a young stuntman he meets recently who works as a delivery man to make a living and has expressed his thoughts about leaving the stunt industry due to his brother's objections, to become his aide and stunt coordinator. Long happily accepts, although his relationship with his worried brother deteriorates.
On the first day of filming, Lee is late because he accompanies his estranged daughter Cherry, [Cecilia Choi], to try on wedding gowns. Meanwhile, Wai's stunt team ignores Long on set and significantly alters Lee's choreography. Learning this, Lee rushes back to the set and engages in heated arguments with Wai, resulting in the early departure of the stunt crew. On Cho and Long's advice, Lee then tries to be more considerate in his filmmaking, while Long soon gains acceptance in the stunt community with his keen sense of choreography. When the producers announce budget cuts, the crew must minimize the scale of a bank robbery scene. However, Lee insists on retaining the gunfight sequences and has the crew shoot unauthorized scenes on the streets. Things go awry when police officers find the actor playing the getaway driver suspicious and interrogates him, causing him to miss the cue for the robber actors' exit. They are forced into an extended gunfight with the police actors. The unsuspecting pedestrians believe it is a real heist and tried to flee the scene, resulting in numerous injuries. Mesmerized by the momentum, Lee ignores the dangers and Wai's suggestion to halt filming, instead asking the cinematographers to focus on the injured pedestrians to capture their raw emotions. This creates further chaos, prompting police officers to respond immediately and arrest Lee and Long, who are playing a robber. Although they are eventually released, the production company has to pay substantial compensation to the injured pedestrians, and the incident draws public backlash. Consequently, Lee is fired from the crew.
Lee overhears Cherry expressing a desire for fireworks at her upcoming wedding, prompting him to request firecrackers from a friend in the props department. However, when he goes to pick them up at the production set, he learns that the climactic explosion scene has been cancelled and that Wai has rearranged all the action choreographies. Enraged, he confronts Wai, leading to a fight. Lee's suit is torn in the process, causing him to arrive late to Cherry's wedding, which angers her and leads her to ignore him all night. Cho contacts Lee, stating that the producers are dissatisfied with the ending and invites him to provide feedback on the rough cut. During the screening, Lee reconciles with Wai, who decides to fund a reshoot of the ending by taking a reduced paycheck. The reshoot begins, culminating in a final shot where Long must leap off a building followed by an explosion. The pulley is damaged in the trial run, and although Long is unharmed, the crew states it will take hours to fix the setup. Lee proposes performing the jump onto cardboard boxes. Initially hesitant, the crew reluctantly agrees when Long volunteers. Just as they collect a few cardboard boxes, Long's brother arrives with many more from his delivery business.
As the crew finishes building the cardboard box bed and Long prepares to jump, Lee advises him to go downstairs and wear more safety pads. At that moment, he informs the main crew that Long is ready, and performs the dangerous jump himself, landing beautifully against the backdrop of a large explosion.
