In the Name of Gerry Conlon opens with Gerry Conlon (played by Daniel Day-Lewis) in his final days, reflecting on his life to journalist Lorenzo Moscia (played by Rami Malek). Through a series of flashbacks, the film chronicles Conlon's journey from a young, rebellious Irishman in Belfast to a falsely accused prisoner in the Guildford Four case.
The flashback sequences show Conlon and his three friends, wrongly convicted for IRA bombings in London, enduring brutal treatment in prison. Conlon's father, Giuseppe (played by Liam Neeson), is also falsely accused and dies in custody. Moscia listens intently as Conlon recounts his struggle for justice and eventual exoneration after serving 15 years in prison. He also shares his experiences with post-traumatic stress disorder and addiction, and how he was able to overcome them with the help of friends and family.
The present-day scenes show Moscia struggling to get Conlon's story published due to lack of interest by publishers and the general public. However, as he spends more time with Conlon, Moscia discovers the universal relevance of his story, particularly in the context of contemporary debates about law and human rights.
As Conlon's health deteriorates, the film culminates in a powerful scene where Moscia reads Conlon's eulogy before a large crowd of supporters. In a final twist, the film reveals that Moscia was able to publish Conlon's story posthumously, and it becomes a bestseller that ignites a wider conversation about wrongful convictions and criminal justice reform.