The second series of the espionage thriller The Undeclared War premieres on Channel 4 tonight, with a repeat broadcast scheduled for 21 July at 21:00.
The drama follows the elite Malware Department of the UK’s intelligence agency as it confronts a foreign‑backed ransomware attack and a mole operating from within.
Actor Simon Pegg returns in the lead role, while Siân Brooke joins the cast as Barbara, a GCHQ analyst and the spouse of Pegg’s character.
Brooke, who expressed a desire to explore period drama and costume work, described the new role as a deliberate shift from the gritty contemporary characters she has portrayed.
To prepare for Barbara, Brooke undertook an intensive language coaching program, noting that the character is fluent in Mandarin, a skill she does not possess.
She also consulted current and former intelligence personnel to gain insight into the covert nature of cyber‑warfare, emphasizing the rapid and far‑reaching consequences of a single malicious command.
The series highlights the concept of “compartmentalisation,” in which operatives keep professional matters strictly separate from personal life, a dynamic that drives tension between the married leads.
Brooke’s recent work includes a high‑profile role as Eurus in Sherlock and a critically acclaimed performance as rookie officer Grace in Blue Lights, for which she received a BAFTA nomination.
Her portrayal in Blue Lights has been praised for its authenticity, drawing on her personal connection to policing through her father’s long career in law enforcement.
Viewers can expect the new episodes to continue blending high‑stakes cyber intrigue with the personal challenges faced by the series’ central couple.
