Three young Muslim men, part of a terror cell, are making a bomb in a London flat, when they get a call to vacate immediately with their gear. The Police have been alerted and they are under suspicion. Asif (Navin Chowdhry), Shahid (San Shella), and Mushtaq (Alex Caan) grab suitcases, the computer, and a cardboard box containing bomb-making equipment and bolt out the door. Shahid's getaway car is clamped, so the three are forced to escape on foot from the pursuing Police. Cornered, they dive into a restaurant on a busy city street. It is the Olympus Grill and dinner is being served to its well-heeled clientele. With the Police outside, Asif, Shahid, and Mushtaq have nowhere to go. Mushtaq, thinking quickly, declares that they will hold the restaurant goers hostage. The diners are forced to get up from their tables. They are lined up against a wall. Electra (Amanda Ryan), the young waitress, is also forced to stand in line. Her mother, who is the restaurant owner, comes out from the kitchen brandishing a rolling pin to find out what is going on. She is Penelope (Stockard Channing), and a rather formidable woman. Penelope at first thinks the three boys want to steal money until they reveal their true intentions. Outside, a sophisticated Police/MI5 operation is underway to release the hostages. Leading the operation is Sofia Warburton (Juliet Stevenson), a forty-five-year-old woman with a strong character, who has sacrificed domestic harmony for her career in the security services. Sofia begins to assemble data gleaned by the Police and information from voice samples and fingerprints to create a profile of the hostage takers. She discovers that Shahid, from a single-parent family, grew up in a rough working class Birmingham council estate, and was a bad boy until he found religion. Asif got a double first in Natural Sciences at Cambridge. He was brought up by his widower father who was prone to beating his kids. Asif works at his father's wine warehouse and was a good taster until he took up Islam, and Mushtaq is the natural leader of the three and has a PhD in physics. The big fear is learning that the terrorists are in possession of red mercury, which can be used to make a dirty bomb with the potential of unleashing untold damage and horror. The three youths have the knowledge and skills to make the bomb. Sofia checks the physics with her estranged husband Lindsey (Nigel Terry), who confirms that it is possible. Time is of the essence. Meanwhile, inside the restaurant, tension mounts as the hostages remain under threat of death from the three gun-wielding terrorists. The hostages are: Sidney (Ron Silver), a middle-aged American management consultant, Amanda (Jacqueline Defferary), a thirty-four-year-old physiotherapist, Neil Ashton (David Bradley), a children's author and his wife Gerry (Stella Gonet), his daughter Jemma (Jessica Brooks), who is a nurse and his adopted mixed-race son Timothy; John (Clive Wood), forty-five, head of a large chemical company and his mistress Janet (Simone Lahbib). And strangely, as days go by and nerves are frayed, the barriers between the hostages and their captors begin to come down. Behind the blank face of terror is scared, confused, and misled youth.