When the bomb goes off in the heart of London, next to the entrance to Liverpool Street Underground station, the city's inadequate emergency services plans are put to an immediate test, with disturbing results for a population ill-prepared to understand or obey anti-contamination and quarantine orders. In addition to touching upon the motivations of the Islamic extremist terrorists to conduct what they saw as a martyrdom operation, the events are shown through the eyes of three principal groups: the government, the emergency medical services, and the police. Nicola Painswick (Helen Schlesinger), Minister for London, and Deputy Assistant Commissioner John Ives (Ewan Stewart) of the Metropolitan Police Anti-Terrorist Branch, present a governmental point of view. Watch Commander Murray Corrigan (Alastair Galbraith) of the London Fire Brigade and his wife Liz Corrigan (Louise Delamere), who works for the National Health Service, present the emergency services' story. Detective Sergeant Mike Drummer (Martin Savage) and Detective Constable Sameena Habibullah (Koel Purie) lead the police investigation to catch the terrorists, under the watchful eye of their boss, Commander Paul Hardwick (Paul Antony-Barber). DC Habibullah, an English Muslim policewoman from Luton, who speaks Urdu, Punjabi, and Arabic, presents a unique point of view throughout the film.