A local radio station in Norwich, known as North Norfolk Digital, finds itself at the mercy of a multinational conglomerate that has just acquired the station. This acquisition heralds a rebranding to "Shape," sending ripples of uncertainty through the staff as they face potential job losses. Amidst this turmoil, DJ Alan Partridge, played by Steve Coogan, remains nonchalant about the changes. However, his co-worker, fellow DJ Pat Farrell, portrayed by Colm Meaney, is consumed by anxiety regarding his job security. Desperate for help, Pat implores Alan to crash a board meeting and lobby the new owners on his behalf.
Things take a turn when Alan stumbles upon the ominous realization that only one of them can remain employed; he ultimately betrays Pat by scrawling "JUST SACK PAT" on a meeting room flipchart. Shortly thereafter, Pat is let go, leading to a tragic fallout.
Later that evening, at a gathering hosted by the new owners of the station, Pat enters North Norfolk Digital with a shotgun, holding staff members hostage. While Alan is outside with his assistant Lynn, played by Felicity Montagu, the situation takes a chaotic turn when Pat begins firing shots. In a panic, Alan commandeers a vehicle and makes his way to the nearest police station just across from the radio station to report the incident.
The police, realizing the precarious situation, compel Alan to act as a negotiator. They establish a command center in a nearby school and send Alan back to the station to communicate with Pat. Throughout this tense standoff, Alan attempts to forge a makeshift connection with Pat, who reveals his only wish is to regain his job. Along with Alan's co-presenter, Sidekick Simon, played by Tim Key, they intermittently host a radio show during the siege.
As the standoff escalates and makes national headlines, Alan grapples with his own fantasies of heroism, albeit he is too afraid to disarm Pat. The situation sees a comical twist when Lynn decides to abandon her usual frumpy style for a televised interview, much to Alan's delight as his ego inflates due to his role in this saga. Additionally, under the pressure of the unfolding drama, Alan awkwardly steals a kiss from a co-worker named Angela, played by Monica Dolan, who had caught his attention earlier.
In a rather humorous yet unfortunate incident, Alan accidentally locks himself out of the station and finds himself losing his trousers in an attempt to gain re-entry through a window. As the police start to lose faith in his negotiating skills, they concoct a plan to send in an undercover officer disguised as a pizza delivery boy. However, Alan interferes and takes the pizzas himself. Upon entering with the pizzas, he encounters a taser hidden in one of the boxes, leading to an argument among the hostages just as the police swarm in.
In a surprising turn of events, Pat manages to escape alongside Alan and his loyal Geordie friend Michael, played by Simon Greenall, using the station's tour bus. During the ride, the unlikely duo continues their radio show, seemingly rebuilding trust. However, when Pat notices Alan's "JUST SACK PAT" scribbled on a photo in the bus, he realizes Alan's betrayal, leading to a tense confrontation. Alan, recognizing the gravity of the situation, attempts to hide in the bus's portaloo, ultimately escaping under the bus through a septic tank.
The gripping conclusion unfolds on Cromer Pier, where Pat confronts Alan with the police looming nearby. In a chaotic moment, Michael attempts to distract Pat by throwing himself off the pier, which fails to have the desired effect. Pat confides in Alan about the profound depression following his wife's death, building an unexpected emotional layer to his character. Unable to pull the trigger on the long-barreled shotgun aimed at himself, Pat hands it over to Alan, who in a moment of panic tosses the gun aside. The weapon discharges, injuring Alan in the leg and causing an unintentional shoulder wound from a police sniper's bullet.
Amidst the chaos, Lynn arrives, mistakenly believing Alan is dead, only to be reassured by a paramedic that he will survive. The film concludes with Alan returning to the now redefined North Norfolk Digital, accompanied by a somewhat shell-shocked Sidekick Simon. Furthermore, the plot twists to reveal that Alan has sparked a new relationship with Angela and is seen departing on a vacation with her and her two sons, towing a boat marked with the title "Alpha Papa." Thus, the story melds chaos, comedy, and character growth into a memorable cinematic conclusion.
