Series 4

12.09.2005 · 57 Min.

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.

13.09.2005 · 59 Min.

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.

22.09.2005 · 59 Min.

Far-right political party The British Way is threatening democracy so Adam and Fiona go undercover to infiltrate and destroy its campaign.

29.09.2005 · 59 Min.

Adam infiltrates a truck carrying illegal immigrants across Europe in order to stop a would-be terrorist.

06.10.2005 · 58 Min.

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.

13.10.2005 · 58 Min.

MI5 suspect a terrorist is planning an attack from his prison cell. Guest stars Jimi Mistry.

20.10.2005 · 59 Min.

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.

27.10.2005 · 59 Min.

An old British traitor is called in to infiltrate a Russian firm suspected of stealing secrets from GCHQ.

03.11.2005 · 58 Min.

Harry upsets the CIA by stopping an extradition to the USA.

10.11.2005 · 59 Min.

A former officer is convinced that MI5 killed Princess Diana and is determined to force the team to prove it.