The group was left reeling after the shocking death of Danny at the hands of hostage-takers as the last season concluded. Now Adam, Harry, Ruth, Fiona and rising star Zafar set out to become even stronger in their battle to safeguard the nation.

Title from container. Created by David Wolstencroft. Originally broadcast on BBC television in 2005. Contains all episodes from the fourth season, including the two part special. Special features: Interviews with cast and crew; audio commentary for each episode; exclusive "making of" documentary.