Overview: When a devastating bomb explodes in central London, causing multiple deaths, a terrorist group with a hatred for human life claim responsibility. With their leader facing extradition, the bombers announce that crippling attacks will be launched at ten hour intervals until he is released.
Overview: Zafar and Adam race against the clock to uncover the latest bomb. As a new ultimatum is issued and Tash mysteriously disapears, the team is forced to deal with the possibility of a mole within their own organisation.
Overview: Far-right political party The British Way is threatening democracy so Adam and Fiona go undercover to infiltrate and destroy its campaign.
Overview: Adam infiltrates a truck carrying illegal immigrants across Europe in order to stop a would-be terrorist.
Overview: A neo-conservative group murder an ex-minister to cover up his past and then they hunt down the journalist who is threatening to blow the story and is under MI5 protection.
Overview: MI5 suspect a terrorist is planning an attack from his prison cell. Guest stars Jimi Mistry.
Overview: The Syrian foreign minister tries to establish subversive contacts with MI5 at the opening of a cultural centre in London. Fiona is desperate to lead this mission and must confront her Syrian past.
Overview: An old British traitor is called in to infiltrate a Russian firm suspected of stealing secrets from GCHQ.
Overview: Harry upsets the CIA by stopping an extradition to the USA.
Overview: A former officer is convinced that MI5 killed Princess Diana and is determined to force the team to prove it.