Season 4 · Episode 4 — Road Trip

When a devastating bomb explodes in central London, causing multiple deaths, a terrorist group with a hatred for human life claim responsib…

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…

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

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 s…

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

The Syrian foreign minister tries to establish subversive contacts with MI5 at the opening of a cultural centre in London. Fiona is despera…

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

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

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