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Season 4 2005

  • 2005-09-11T23:00:00Z on BBC One
  • 60 mins
  • 8 hours, 39 mins (10 episodes)
  • United Kingdom
  • English
  • Drama, Action, Adventure, Thriller

The group are still reeling after the shocking events at the end of the last series. Now rising star Zafar joins the team as they set out to become even stronger in their battle to safeguard the nation. When London comes under terrorist attack Adam is forced to make an impossible decision, Harry must deal with blackmail threats from an old flame, and Fiona faces her own demons when she goes undercover in Syria.

10 episodes

4x01 Episode 1

  • Season Premiere

    2005-09-11T23:00:00Z — 52 mins

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.

4x02 Episode 2

  • 2005-09-12T23:00:00Z — 52 mins

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.

4x03 Episode 3

  • 2005-09-18T23:00:00Z — 52 mins

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

4x04 Episode 4

  • 2005-09-25T23:00:00Z — 51 mins

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

4x05 Episode 5

  • 2005-10-02T23:00:00Z — 52 mins

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.

4x06 Episode 6

  • 2005-10-09T23:00:00Z — 52 mins

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

4x07 Episode 7

  • 2005-10-16T23:00:00Z — 52 mins

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.

4x08 Episode 8

  • 2005-10-23T23:00:00Z — 52 mins

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

4x09 Episode 9

  • 2005-10-23T23:00:00Z — 52 mins

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

4x10 Episode 10

  • 2005-10-31T00:00:00Z — 52 mins

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