MI-5

The team track a boat carrying a lethal load, fearing it is headed for Plymouth.

The pressure is on for Beth when she goes undercover for MI5 for the first time.

Section D hunt for a rogue nationalist from the ex-Soviet state of Azakstan.

The team try to learn the reason for a visit from a trio of highly skilled Chinese agents

Beth and Dimitri go undercover when the US president arrives to chair secret peace talks.

Relations between the CIA and MI5 are stretched after a drone is hacked in Afghanistan.

Lucas is plunged further into the depths of his past.

The team face their toughest ever challenge: tracking down Section Chief Lucas North.