Spooks returns with Section D still reeling from Ros Myers’ death – and unrest and suspicion is rife as new faces join them in their operations.

An industrial estate in Bermondsey, London, is home to The Grid, Spooks‘ fictional hi-tech nerve centre. This is where much of the ninth series of BBC1’s hit MI5 drama is based. On our arrival, Total TVguide is shown to a large white room, which is virtually empty apart from a few tables and chairs…appropriately, it feels like an interrogation chamber.

We are given a tour of the set later, but first we’re in the rather stark space to meet Spooks‘ new cast members, starting with Sophia Myles. She plays Beth Bailey, an undercover mercenary who met Harry Pearce (Peter Firth) years ago and now wants a job at The Grid.

“Beth’s based on a real woman, who I’ve met,” says Sophia, 30. “When she [the real person] was 18 – and studying English at Edinburgh University – she was head-hunted by MI6. She was picked to undergo their fast-track selection process. It’s about two blocks of six months.”

Sophia is not the only newcomer to the show, the latest series will see Iain Glen (The Diary of Anne Frank), stage actor Simon Russell Beale and Primeval‘s Laila Rouass all appear. Max Brown, who played Sam Grey in Mistresses, also takes on a major role as Special Boat Service (SBS) member Dimitri Levendis.

“I hadn’t heard of the SBS before,” says Max, 29. “They’re like the SAS, but they work below or on the water, basically. They only do black ops, so they’re always undercover, and the SAS have taken a lot of gold starts for the work they’ve done, apparently.”

Some of the new arrivals cause unrest in Section D, and the MI5 agents wonder who can be trusted as they go about their operations.

This week, the team is still mourning Ros Myers’ death, and Harry is intent on exacting revenge. But the counter-terrorism chief also realises how much MI5 analyst Ruth Evershed (Nicola Walker) means to him and asks her to marry hm.

Elsewhere, Lucas North (Richard Armitage) finds himself on a ship in Tangier, tracking an Al Qaeda operative, along with Dimitri, who’s undercover as the ship’s captain. But they’re hijacked by Somali pirates, and help comes from Beth, who’s posing as an Eastern European prostitute.

By the finale, Lucas receives an unwelcome visit from someone, but this is just one of many shocking revelations about his past…

An Essex port doubled up as Tangier for filming reveals Max. “It’s Tilbury Docks for all the exteriors, filmed through a yellow lens to make it look hotter,” he smiles.

Max admits to being a big fan of Spooks already, but Sophia had never seen it prior to getting the job. “I couldn’t watch it late at night because it would stress me out,” Sophia explains.

So what drew her to the role? “I’d been in LA for two years, working on a TV show for Warner Bros [vampire drama Moonlight]. The homesickness I experienced was so painful I was absolutely desperate to come back to London. So I prayed for an acting job that would allow me to sleep in my own bed, and my wish came true, thankfully.”