Season 4

Craven and Haggerty are assigned to investigate if a photographer is a threat to national security.

The team are on the trail of Rehfuss - a deadly assassin who has managed to get into the country.

Craven and Haggerty are hot on the trail of a traitor has broken out from prison.

An experimental weapon is stolen from a military research facility, but the thieves are unaware the weapon is unstable.

Tensions run high as Craven and Haggerty investigate two army officers.

Craven provides security for the debriefing of a captured KGB agent.

Craven and Haggerty investigate the broadcasting of compromising information about public figures on a pirate radio station.

Craven is appalled to find himself implicated in his ex-wife's terrorist activities.

Craven must unravel the connection between a recently-killed spy and an au pair.

Craven has to investigate a morally dubious but strategically important foreign VIP who has been robbed of a fortune in diamonds.

A German student revolutionary has been allowed into Britain under the strict condition that he does nothing political. Craven and Haggerty are made to ensure that he sticks to the terms of his deal.

Is Strand's erratic behaviour a result of the pressure he is under or is he playing a much more dangerous game?

Craven and Haggerty are working against the clock to find a gunman stalking the London streets.