In the late 2010s,
Liam Óg Ó hAnnaidh and
Naoise Ó Cairealláin are part of the "
ceasefire generation" living in the
Gaeltacht Quarter of West
Belfast. Growing up, they learnt to speak
Irish from Naoise's father, Arlo, a former
republican paramilitary who faked his death to evade British authorities. As a result, his wife, Dolores, has become a recluse while Arlo lives in hiding and is disappointed with his son's hedonistic lifestyle and lack of initiative. One night, Liam is arrested at a drug-laden party. He outrages the
police with his refusal to speak English, insisting he can communicate only in Irish.
JJ Ó Dochartaigh, a music teacher at an
Irish-language immersion school, is summoned to serve as an interpreter during Liam's interrogation. He helps Liam avoid charges. He also hides a notebook of Liam's that he discovers contains drugs, slipping it into his pocket. JJ notices that the notebook contains satirical verses written in Irish and decides to set them to music as rap lyrics. He approaches Liam and Naoise with the idea of forming an Irish-language
hip-hop group, arguing that the music would be a way to bring the Irish language to
Millennials and
Generation Z. Meanwhile, Liam begins a relationship with a
Protestant girl named Georgia. Liam names the group "
Kneecap", after
the infamous punitive torture technique common in
Northern Ireland during
the Troubles. The trio create a track together during an all-night, drug-fueled recording session. They start performing live, and their music draws crowds. JJ fears the damage to his teaching career that might result from a public connection with Kneecap's confrontational and blatantly political music, and so performs as the anonymous "DJ Próvaí", wearing an Irish tricolour
balaclava to hide his face during gigs. He also conceals his involvement in the band from his girlfriend, Caitlin, who is heavily involved in the campaign for an
Irish Language Act that would officially recognise the
Irish language in Northern Ireland. As Kneecap grow in popularity, they face controversy for promoting
anti-social behaviour and outspoken republicanism in their lyrics. A
dissident republican organisation calling themselves "
Radical Republicans Against Drugs" (RRAD) threaten and attack Liam and Naoise. The garage containing Kneecap's recording studio and their recorded music is bombed, and the group believe RRAD is responsible. With a tight deadline to produce a new track for
RTÉ Raidió na Gaeltachta, the group break into the music department of the school where JJ works and record a song overnight using the equipment there. The song is initially banned from the radio due to its lyrical content, but after Dolores organises a protest campaign, the song is aired and becomes a hit. With his identity as DJ Próvaí now public, JJ is fired from his teaching job, and Caitlin breaks up with him. With little left to lose, after some hesitation, JJ decides to remain part of Kneecap, despite having announced that he was quitting. At a major gig, Kneecap publicly humiliate RRAD by playing an audio recording of its members demanding that Liam and Naoise turn drug money over to them. Enraged, an RRAD member in the crowd fires a gun and, in the ensuing chaos, Liam is apprehended by the police and Naoise is captured by RRAD.
Police Service of Northern Ireland Detective Ellis, an
Ulster Loyalist and Georgia's aunt, viciously beats Liam before revealing that
she arranged for the studio to be bombed in an attempt to halt Kneecap's rise to fame, having previously warned JJ and Dolores of the damage it would bring. Meanwhile, RRAD is preparing to kneecap the kidnapped Naoise when Arlo appears on the scene. Initially pretending that he intends to punish his son himself. Arlo instead shoots the three RRAD members and tells Naoise that he is proud of him and his music. He allows himself to be arrested while Liam is grudgingly released from police custody. Kneecap's music becomes ever more popular despite the Protestant establishment doing everything in their power to stop them. Meanwhile, Caitlin continues her political campaign for the Irish Language Act, Dolores is shown singing in a pub (having overcome her
agoraphobia), and Georgia and other students of all ages and backgrounds participate in an Irish-language class. ==Cast==