Sandrine is increasingly fraught. Peter Westbourne tracks her down, but fails to calm her. Sandrine returns to the army base, retrieves her gun and disappears. Faced with a second murder, Kip and Nathan struggle to figure out how the two killings are... (more) connected. Kip is convinced that MI5 is leaking information to the media.

Billie Piper, Carey Mulligan, John Simm, Nicola Walker