Main Overall •
Holliday Grainger as Rachel Carey – A fast-track detective whose career is defined by a ruthless ambition and a rigid, often isolating moral compass. While highly capable and headstrong, she is frequently viewed as "spiky" and "plain-speaking," traits that often place her at odds with her superiors and leave her with few personal allies. Despite her tactical sharpness, her commitment to accountability leads her trust in her own integrity to be pushed to its breaking point •
Lia Williams as
DSU Gemma Garland – An inscrutable and glacial senior intelligence official within
SO15. A pragmatic operative who prioritises national security over transparency, she frequently employs morally ambiguous methods to protect state interests. •
Ron Perlman as Frank Napier – A powerful and cynical
CIA Section Chief who utilises ruthless, clandestine tactics to protect American interests. He oversees covert state operations with a pragmatic disregard for legal transparency. •
Ben Miles as Danny Hart – The
Commander of
SO15 who oversees counter-terrorism operations. While a staunch defender of national security, he is increasingly conflicted by the ethical cost and systemic deception involved in covert state programmes. •
Ginny Holder as
DS (later
DI) Nadia Latif – A principled and methodical detective who relies on empirical facts over intuition. Her process-driven approach often leads her to identify the technical anomalies that expose larger conspiracies. •
Cavan Clerkin as
DS Patrick Flynn (series 1–2) – seasoned, street-smart detective and pragmatic ally to Carey. Despite initial scepticism of her career path, he provides a grounded perspective while assisting her in navigating complex investigations. •
Paapa Essiedu as Isaac Turner
MP (series 2–3) – The
Minister of State for Security and a rising political star. After his career and personal life are upended by a real-time deepfake hack, he becomes an ally to Carey in her attempt to expose 'Correction'. •
Indira Varma as Khadija Khan (series 2–3) – A fierce and high-profile
BBC News presenter and
investigative journalist. Ambitious and ruthlessly pragmatic, she prioritises her own career advancement and the pursuit of high-stakes information over personal loyalty, often operating on a strictly transactional basis.
Series 1 •
Callum Turner as Shaun Emery – A former British Army
Lance Corporal who is released from prison after a successful appeal against a war crime conviction. A determined and protective father, he soon finds himself at the centre of a new criminal investigation after incriminating CCTV footage appears to show him assaulting his barrister. •
Laura Haddock as Hannah Roberts – A brilliant and principled human-rights
barrister who successfully represents Shaun Emery during his appeal. Her sudden disappearance, and her apparent assault caught on CCTV, triggers a major police investigation. •
Barry Ward as Charlie Hall – A
solicitor and close colleague of Hannah Roberts who works to secure Shaun Emery's initial release. He is a member of the "Pilgrims of Justice," an activist group dedicated to exposing flaws in the surveillance state. •
Ralph Ineson as
DCI Alec Boyd – An experienced detective who oversees the investigation into Hannah Roberts’ disappearance and manages the procedural pressures of the high-profile investigation. • Alexander Forsyth as Eli Jacobi – A
CIA analyst working in a covert London-based unit. A skilled digital expert, he becomes a key figure in the investigation when he appears to act as a whistleblower regarding the use of manipulated surveillance footage.
Series 2 •
Charlie Murphy as Simone Turner – The wife of Isaac Turner who faces increasing strain as a result of the inflammatory public statements attributed to her husband. She struggles to protect her family's privacy while navigating the resulting tensions and distrust within her marriage. • Joseph Arkley as Gregory Knox – The calculating and ambitious CEO of Truro Analytics, a powerful data analytics firm that specialises in using advanced algorithms and artificial intelligence to influence public opinion. •
Natalie Dew as Aliza Clarke – A dedicated
Special Adviser who manages the Minister's public profile and policy development. • Harry Michell as Rhys Edwards – A pragmatic and cynical
Special Adviser who manages the Minister's strategic communications.
Series 3 •
Killian Scott as Commander Noah Pierson, the mysterious new permanent head of
SO15 •
Hugh Quarshie as
Commissioner Cameron Yates, Head of the
Metropolitan Police •
Andrew Buchan as
Deputy Commissioner Julian Talbot, Yates's second in command •
Isabella Brownson as Paige Thomas, a police communications official •
Linus Roache as
Colonel Christopher Figgis, the commanding officer of
E Squadron •
Jonathan Aris as
Major Peter Neuman, a
military doctor in E Squadron
Supporting Overall •
Daisy Waterstone as Abigail Carey – Rachel's younger half-sister •
Nigel Lindsay as
DCI Tom Kendricks – A senior SO15 official and tactical lead who ensures operational stability within the
CTC control centre. A long-term colleague of Rachel Carey, he provides logistical oversight and support during her investigations. • Tessa Wong as
DC Chloe Tan (series 2–3) – A diligent and observant fast-track detective. Emerging as a "shadow" of Rachel Carey, she provides meticulous, data-driven support for investigations while striving to prove herself as a key member of the team. •
Andy Nyman as Sir Rowan Gill (series 2–3) – The
Home Secretary and Isaac's superior at the
Home Office. A seasoned politician, he is one of the few officials with high-level knowledge of the "Correction" programme.
Series 1 •
Sophia Brown as Karen Merville – Shaun's former partner and the mother of his young daughter. She is wary of his release and remains deeply concerned for their daughter's well-being as the legal and media scrutiny surrounding him intensifies. •
Alan Williams as Eddie Emery – Shaun's grandfather who provides him with a place to stay and emotional stability following his release. He remains a steadfast believer in his grandson's innocence as the criminal investigation and media attention intensify. •
Paul Ritter as Marcus Levy – A seasoned broadcast consultant and video engineer who provides the expert technical evidence required to secure Shaun's initial release. He later assists Rachel Carey by theorising how CCTV footage could be manipulated through "delayed" transitions. •
Famke Janssen as Jessica Mallory – A high-ranking official from the
Office of the Director of National Intelligence and Frank Napier's superior. She arrives in London to oversee American interests in the "Correction" programme and ensure the integrity of the operation remains intact. •
Sharon Rooney as Becky – A local authority CCTV footage monitor who first spots the apparent assault of Hannah Roberts while on duty. Her report to the emergency services triggers the police's involvement and the subsequent manhunt for Shaun Emery.
Series 2 •
Rob Yang as Yan Wanglei – The UK Head of the Chinese
artificial intelligence company XANDA, who leads the firm's bid for a government contract to implement facial recognition technology at British borders. • Joshua Jo as Edison Yao – A
computer scientist and Chinese
dissident who acts as a key witness for the China Research Committee. His assassination serves as the catalyst for the investigation into a new form of digital manipulation. •
Angus Wright as Anthony Reed
OBE – The
BBC's Security Correspondent who serves as a high-level contact for the intelligence services. He is called to manage sensitive information and coordinate the media's response to emerging national security crises.
Series 3 •
Amanda Drew as Angela Stilton, Head of Communications for the Metropolitan Police •
Joe Dempsie as James Whitlock, a convicted criminal accused of being an assassin •
Adrian Rawlins as Lord Justice Frederickson, chair of the Correction
Inquiry • Jude Mack as Natasha Hayes, a
BBC News journalist working for Khadija Khan ==Episodes==