Plot
Kat Bryant is teaching improv classes in London, having made no career or relationship progress in a decade while her friends are all established. Among her new students are Marlon and Hugh. Marlon is an unsuccessful actor whose detailed character research and inclination toward dramatic monologues results in failed auditions and abandonment from his agent. Hugh is a lonely and insecure technical support worker at a brokerage, where he has been cautioned for inappropriate attempts at socializing. Detective Sergeant Graham Billings of the Metropolitan Police recruits the three for a low-level undercover sting operation. [a]
The trio are sent to expose a convenience store's participation in the illicit cigarette trade. Kat, as "Bonnie", leads as point; Marlon, as "Roach", covers as her wingman; and Hugh, as "The Squire", covers their backs and watches the door. They succeed in their task but Marlon's uncompromising character demands more and the clerk drives them to mid-level drug dealer Fly who offers to sell them three bricks of cocaine. They are about to close the deal when an Albanian gang burst in, as Fly's associate Shosh had earlier stolen the cocaine from them. [b] Kat calms the situation and claims that she is selling the cocaine to Fly, but instead sells it to the Albanians who leave peacefully.
Billings insists that the undercover operation continue. The trio return to Fly for work, and he sends them to collect a debt from Sagar, a retired hitman. Marlon's theatrics successfully intimidate Sagar who flees and is fatally struck by a van. Detective Inspector Dawes leads the police investigation of Sagar's death, and suspects the trio are professional criminals taking over the local drug trade.
Fly is pleased when the trio return with the money and celebrates his birthday with them. During the night they encounter Kat's friends who are scared away by Fly and Shosh. The trio accompany Fly to a meeting with his boss, Metcalfe, who reveals that he had a business arrangement with the Albanians which has been jeopardized by recent events.
Kat wants to quit, believing Metcalfe is too dangerous, but Billings insists that they continue. They attempt to negotiate with dealer K-Lash for more cocaine, but she doesn't have any. Marlon tries to intimidate her but his bluffs are exposed, forcing them to flee. Billings arrives and is shown to be corrupt, blackmailing the trio. He is the only one who can prove their innocence, but Shosh arrives and kills him. Metcalfe is convinced that Billings had an informant.
While disposing of Billings's body, the trio lose their vehicles during a police chase. Kat goes to a dinner party which is actually an intervention, given her sudden and secretive change in behaviour. Kat dramatically confesses to needing help while Marlon steals car keys, and Hugh defends the body from a neighbourhood dog. They drive away, meet Shosh and bury the body.
Kat and Marlon learn that Metcalfe is having Billings' phone hacked and try to retrieve it, but it is a trap which exposes them as the informants. Fly takes them to a remote area and feigns killing them but lets them go, liking them and believing that Metcalfe went too far. The three consider fleeing the country but they are arrested by the police.
Dawes learns the trio's real identities and is reluctant to file charges, but is under pressure to deliver major drug arrests. Kat suggests sending them in undercover to work Fly as an informant, since he trusts them and is disillusioned with Metcalfe. Fly wears a wire but as part of a drug exchange Metcalfe gives Fly to the Albanians for execution. The trio intervene, pretending to be undercover police officers to extract Fly. They succeed in the bluff and get Metcalfe to incriminate himself. The police rush in and make arrests, while Shosh kills Metcalfe to protect Fly and the trio. Fly, learning that they are improv actors, rewards them each with cash from Metcalfe's briefcase.
Afterwards, Marlon impresses a casting agent with his authenticity, Hugh pursues his passion by opening a wine shop, and Kat's improv group becomes immensely popular amid rumours of their undercover work.
- ↑ Billings initially suggests that improv actors are better suited to staying in character in unexpected scenarios.
- ↑ Shosh steals the cocaine from the Albanians in an action sequence shown in the film's introduction.
