# The Undeclared War
**The Undeclared War** is a British cyber-thriller television series created by Peter Kosminsky and Colin Callender for Channel 4 and Peacock, set in 2024 in the run-up to a British general election and following analysts at GCHQ, the UK's Government Communications Headquarters, as they defend the country from cyber-attacks.[1](https://www.channel4.com/press/press-pack/undeclared-war-press-pack) The first season, six episodes directed by Kosminsky, premiered on [Channel 4](https://www.edgepedia.org/channel-4) on 30 June 2022 and streamed on Peacock from 18 August 2022.[1](https://www.channel4.com/press/press-pack/undeclared-war-press-pack) • [2](https://www.rottentomatoes.com/tv/the_undeclared_war) A second season of six episodes, written by Colin Teevan and directed by Paul McGuigan, returned in 2026 after a four-year gap.[3](https://www.channel4.com/press/press-pack/undeclared-war-series-two-press-pack)
| Key fact | Detail |
|---|---|
| Original run | Season 1 premiered 30 June 2022 on Channel 4; six episodes, all directed by Peter Kosminsky, who wrote four[1](https://www.channel4.com/press/press-pack/undeclared-war-press-pack) |
| Setting | Post-pandemic 2024, in the run-up to a British general election, with GCHQ analysts countering cyber-attacks on the UK's electoral system[1](https://www.channel4.com/press/press-pack/undeclared-war-press-pack) |
| Lead cast | Hannah Khalique-Brown as intern Saara Parvin; Simon Pegg as GCHQ Head of Operations Danny Patrick; Mark Rylance in a guest role; Adrian Lester as fictional Prime Minister Andrew Makinde[4](https://www.independent.co.uk/arts-entertainment/tv/reviews/undeclared-war-review-simon-pegg-b2113112.html) |
| Production companies | Playground, Stonehenge Films, and Universal International Studios / Universal Global Television for Channel 4 and Peacock[1](https://www.channel4.com/press/press-pack/undeclared-war-press-pack) • [3](https://www.channel4.com/press/press-pack/undeclared-war-series-two-press-pack) |
| Season 2 | Six episodes written by Colin Teevan, directed by Paul McGuigan, first aired July 2026 on Channel 4 and streamed on Peacock from 27 August 2026[3](https://www.channel4.com/press/press-pack/undeclared-war-series-two-press-pack) • [5](https://www.tomsguide.com/entertainment/streaming/5-biggest-new-shows-to-stream-this-week-including-the-return-of-an-apple-tv-sci-fi-thriller) |
| Reception | Rotten Tomatoes scores of 68% for season 1 and 57% for season 2; season 1 Metascore 58 on Metacritic[2](https://www.rottentomatoes.com/tv/the_undeclared_war) • [6](https://www.metacritic.com/tv/the-undeclared-war/critic-reviews/) |
| Expert response | Cybersecurity specialist Alan Woodward, visiting professor at the Surrey Centre for Cyber Security, called the depiction of the attack on UK internet infrastructure credible[7](https://www.theguardian.com/tv-and-radio/2022/jul/07/some-staff-work-behind-armoured-glass-a-cybersecurity-expert-on-the-undeclared-war) |
## Spoilers
### Premise and season one
The series opens on the first day of Saara Parvin ([Hannah Khalique-Brown](https://www.edgepedia.org/hannah-khalique-brown)), a second-year computer science student at London University who wins a work-experience placement at GCHQ's Malware Department. Her arrival coincides with a stress-test of UK telecommunications infrastructure during which a significant part of the UK's internet suddenly goes down; what first looks like a consequence of the test is shown to be a deliberate attack.[8](https://www.channel4.com/press/news/episodic-synopsis-undeclared-war) Saara spots a hidden section of the malware that everyone else has missed, and her discovery propels her into the center of an escalating data war with Russia.[9](https://www.channel4.com/press/news/interview-peter-kosminsky-creator-writer-director-executive-producer) • [2](https://www.rottentomatoes.com/tv/the_undeclared_war)
**Political backdrop.** In the show's near-future Britain, Boris Johnson has been replaced as prime minister by Andrew Makinde ([Adrian Lester](https://www.edgepedia.org/adrian-lester)), the country's first Black prime minister and a Conservative, who fears the electoral consequences of a cyberattack.[4](https://www.independent.co.uk/arts-entertainment/tv/reviews/undeclared-war-review-simon-pegg-b2113112.html) The supporting cast includes [Simon Pegg](https://www.edgepedia.org/simon-pegg) as Danny Patrick, GCHQ's Head of Operations; [Alex Jennings](https://www.edgepedia.org/alex-jennings) as David Neal, the Head of GCHQ; Ed Stoppard as Richard Marston; and Mark Rylance, who appears in the GCHQ canteen scenes of episode two.[4](https://www.independent.co.uk/arts-entertainment/tv/reviews/undeclared-war-review-simon-pegg-b2113112.html) • [7](https://www.theguardian.com/tv-and-radio/2022/jul/07/some-staff-work-behind-armoured-glass-a-cybersecurity-expert-on-the-undeclared-war)
**The Russian side.** Episode three shifts perspective to Vadim Trusov ([German Segal](https://www.edgepedia.org/german-segal)), Saara's classmate, who returns to St Petersburg when Russian students are ordered to leave the UK. He reluctantly joins Glavset, a covert organization that uses social media to influence British public opinion, and is later forced to use his coding talents to support Russia's cyber warfare efforts at the FSB, growing increasingly uneasy about what he learns.[8](https://www.channel4.com/press/news/episodic-synopsis-undeclared-war) Later episodes deal with irregularities in the UK general election results and a threat to GCHQ's intelligence cooperation with the United States.[8](https://www.channel4.com/press/news/episodic-synopsis-undeclared-war)
### Season two
The second season, set immediately after the end of season one, follows the Malware Department as it deals with the fallout of the massive Russian cyber-attack. Just as Britain gains the upper hand, Danny's team realizes Russia was not the real architect of the attack, that a new adversary is preparing to strike, and that there is a mole inside GCHQ.[3](https://www.channel4.com/press/press-pack/undeclared-war-series-two-press-pack) The season introduces Siân Brooke as Barbara Patrick, Danny's wife, a former MI5 officer now working as a GCHQ analyst; Danny Sapani as Charlie Francis, GCHQ's Head of Security; and [Chloe Pirrie](https://www.edgepedia.org/chloe-pirrie) as Lt Colonel Roz Cavendish, seconded to GCHQ as Director of Rapid Response in a move Danny reads as a threat to his authority.[3](https://www.channel4.com/press/press-pack/undeclared-war-series-two-press-pack) Episode synopses point to a Chinese dimension, with Danny and Roz clashing over China, Chinese malware causing havoc in British government departments, and Vadim held in captivity in Shenzhen.[3](https://www.channel4.com/press/press-pack/undeclared-war-series-two-press-pack)
Kosminsky did not return as director; Paul McGuigan (*Sherlock*, *Inside Man*) directed all six episodes, and Colin Teevan (*Das Boot*, *Rebellion*) wrote the season.[3](https://www.channel4.com/press/press-pack/undeclared-war-series-two-press-pack) The Guardian noted that carrying the timeline straight on from the original meant the new run was now set two years in the past rather than in a near future.[11](https://www.theguardian.com/tv-and-radio/2026/jul/21/the-undeclared-war-review-simon-pegg) The season aired on Channel 4 in July 2026 and all six episodes streamed on Peacock from 27 August 2026.[5](https://www.tomsguide.com/entertainment/streaming/5-biggest-new-shows-to-stream-this-week-including-the-return-of-an-apple-tv-sci-fi-thriller)
## Research and realism
Kosminsky described the series as fiction based heavily on research carried out over a number of years, intended as a cautionary tale about scenarios he said were being war-gamed by security services, and noted that cyber conflict is a relatively cheap domain in which to fight a war.[9](https://www.channel4.com/press/news/interview-peter-kosminsky-creator-writer-director-executive-producer) The project grew out of his earlier collaboration with producer Colin Callender on *Wolf Hall*.[9](https://www.channel4.com/press/news/interview-peter-kosminsky-creator-writer-director-executive-producer)
The technical detail drew specific praise from practitioners. Alan Woodward, a computer scientist and visiting professor at the Surrey Centre for Cyber Security, wrote that the episode-one attack was credible: the script specified that the BT infrastructure carrying a large share of UK web traffic had been taken offline, that 55% of web access had been lost, and that the attack was timed to be disruptive rather than catastrophic. He placed the scenario alongside real incidents such as the 2016 Dyn DNS attack and the [SolarWinds](https://www.edgepedia.org/solarwinds) compromise.[7](https://www.theguardian.com/tv-and-radio/2022/jul/07/some-staff-work-behind-armoured-glass-a-cybersecurity-expert-on-the-undeclared-war) The University of Gloucestershire built a series of cyber webinars around the questions the drama raised, drawing on industry figures including Professor Buck Rogers, formerly Chief Information Security Officer at the [Bank of England](https://www.edgepedia.org/bank-of-england).[10](https://www.glos.ac.uk/content/questions-raised-by-channel-4-thriller-are-up-for-discussion-at-new-series-of-cyber-webinars/)
## Production
The series is a co-production of [Playground](https://www.edgepedia.org/playground), Stonehenge Films, and [Universal International Studios](https://www.edgepedia.org/universal-international-studios) (Universal Global Television for season two) for Channel 4 and Peacock, executive produced by Colin Callender, Daniel Gratton, Noëlette Buckley, Peter Kosminsky, Colin Teevan, and Paul McGuigan, with Caroline Levy producing.[1](https://www.channel4.com/press/press-pack/undeclared-war-press-pack) • [3](https://www.channel4.com/press/press-pack/undeclared-war-series-two-press-pack) It received support from the Welsh Government via Creative Wales, and season one filmed in Bristol.[3](https://www.channel4.com/press/press-pack/undeclared-war-series-two-press-pack) • [12](https://filmbristol.co.uk/wordpress/wp-content/uploads/2022/06/NEWS-The-Undeclared-War-begins-30-Jun-on-Channel-4-after-filming-in-Bristol-FINAL-30-June-22.pdf) Cinematographer Gavin Finney, BSC worked with Kosminsky on the series.[13](https://www.leitz-cine.com/production/the-undeclared-war-2022)
## Reception
Critical response to season one was mixed. The season holds a 68% Tomatometer on Rotten Tomatoes and a Metascore of 58 on Metacritic, labeled mixed or average.[2](https://www.rottentomatoes.com/tv/the_undeclared_war) • [6](https://www.metacritic.com/tv/the-undeclared-war/critic-reviews/) Positive reviews included Radio Times, which wrote that the series guides viewers through the complex world of cybersecurity and refuses to relinquish its grip until the final episode, and [The Times](https://www.edgepedia.org/the-times), which credited Kosminsky with bringing an invisible cyberwar with Russia to the screen without making the characters glamorous.[6](https://www.metacritic.com/tv/the-undeclared-war/critic-reviews/) The Independent was negative, calling the drama politically muddled and criticizing stylized vignettes of the coding process, while still acknowledging the substance of its subject.[4](https://www.independent.co.uk/arts-entertainment/tv/reviews/undeclared-war-review-simon-pegg-b2113112.html) Season two scored 57% on Rotten Tomatoes; a Guardian review found it had more zip than its predecessor but judged the subject inherently undramatic on screen.[2](https://www.rottentomatoes.com/tv/the_undeclared_war) • [11](https://www.theguardian.com/tv-and-radio/2026/jul/21/the-undeclared-war-review-simon-pegg)
## References
1. [The Undeclared War – Press Pack, Channel 4](https://www.channel4.com/press/press-pack/undeclared-war-press-pack)
2. [The Undeclared War, Rotten Tomatoes](https://www.rottentomatoes.com/tv/the_undeclared_war)
3. [The Undeclared War Series Two – Press Pack, Channel 4](https://www.channel4.com/press/press-pack/undeclared-war-series-two-press-pack)
4. [The Undeclared War review, The Independent (30 June 2022)](https://www.independent.co.uk/arts-entertainment/tv/reviews/undeclared-war-review-simon-pegg-b2113112.html)
5. [5 biggest new shows to stream this week, Tom's Guide](https://www.tomsguide.com/entertainment/streaming/5-biggest-new-shows-to-stream-this-week-including-the-return-of-an-apple-tv-sci-fi-thriller)
6. [The Undeclared War critic reviews, Metacritic](https://www.metacritic.com/tv/the-undeclared-war/critic-reviews/)
7. ['Some staff work behind armoured glass': a cybersecurity expert on The Undeclared War, The Guardian (7 July 2022)](https://www.theguardian.com/tv-and-radio/2022/jul/07/some-staff-work-behind-armoured-glass-a-cybersecurity-expert-on-the-undeclared-war)
8. [Episodic Synopsis – The Undeclared War, Channel 4](https://www.channel4.com/press/news/episodic-synopsis-undeclared-war)
9. [Interview: Peter Kosminsky (creator, writer, director & executive producer), Channel 4](https://www.channel4.com/press/news/interview-peter-kosminsky-creator-writer-director-executive-producer)
10. [Questions raised by Channel 4 thriller to be discussed at new series of cyber webinars, University of Gloucestershire](https://www.glos.ac.uk/content/questions-raised-by-channel-4-thriller-are-up-for-discussion-at-new-series-of-cyber-webinars/)
11. [The Undeclared War review – Simon Pegg's cyber-attack thriller fails to push any of the right buttons, The Guardian (21 July 2026)](https://www.theguardian.com/tv-and-radio/2026/jul/21/the-undeclared-war-review-simon-pegg)
12. [The Undeclared War begins 30 Jun on Channel 4 after filming in Bristol, Film Bristol](https://filmbristol.co.uk/wordpress/wp-content/uploads/2022/06/NEWS-The-Undeclared-War-begins-30-Jun-on-Channel-4-after-filming-in-Bristol-FINAL-30-June-22.pdf)
13. [The Undeclared War (2022), Leitz Cine](https://www.leitz-cine.com/production/the-undeclared-war-2022)
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*Topic: Encyclopedia › Arts and culture › Screen and stage › Film and television › Series and fictional screen worlds › Scripted television and comedy series › Drama and prestige series (individual series) › Crime and thriller series › Spy and political thrillers*
*Initially written Oct 3, 2026 · Reviewed: Oct 25, 2026 · Edited: Oct 15, 2026; Oct 25, 2026; Nov 1, 2026 · Last review: Oct 25, 2026*
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