Spooks returns to BBC One this autumn for a ninth series. Richard Armitage, who plays MI5 agent Lucas North, reveals what’s in store.

What can viewers expect from the new series of Spooks?

“This year the storylines feel very politically current but we also learn a lot more about the team. Who are these people, what lies beneath the surface, who are they true to, what secrets do they hide in order to do their jobs? Deception and betrayal are key. Of course there are also exciting and intriguing stories of the week but the overall series arc really unravels the character of Lucas North and blows his whole world apart. His loyalty and his future at MI5 are all under the microscope.”

How does Ros’s death affect Lucas and the rest of the team?

“Ros’s death has rocked everyone’s world. The feeling is that if someone as skilled as Ros can go down, then no one is safe. It has made everyone really question what it means and what price can be paid doing the job. On a practical level it leaves Harry with no choice but to make Lucas head of Section D. Lucas has longed for Harry’s trust and acceptance but he has received it by default and it is bittersweet.”

What’s it been like working with new actors/characters? Has it made you feel like one of the old school?

“The series opens with the introduction of four new characters: Beth Bailey and Dimitri Levendis, played by Sophia Myles and Max Brown; a new Home Secretary played by Simon Russell Beale; and Vaughn, a character from Lucas’s past, played by Iain Glen. I feel a bit like the older generation as it feels like a new “‘super spook generation” has come on board. Dimitri is ex-SBS, and Beth comes from a background in private security, a “mercenary” as Lucas puts it. He presses Harry to allow him to assemble this team. Dimitri is solid, useful and youthful but Beth is a bit of a liability. Viewers will have to wait and see if she becomes a member of Section D or not.”

Vaughn turns up from Lucas’s past. What does he want? How does it affect Lucas?

“It’s been 15 years since Lucas last saw Vaughn and, when they meet, Vaughn has a suitcase which contains an assortment of material from Lucas’s life prior to joining MI5. Lucas finds a photograph of a girl, Maya – his old girlfriend. It is the beginning of a journey which Vaughn will control and it takes Lucas to the very edge.”

Who is Maya?

“Maya is Lucas’s first love; a woman he had to leave just as their life together was beginning. Some 15 years ago, Lucas vanished from Maya’s life; one day he was there and the next he was gone. Just like a spook. He wants her back and she is the key to who Lucas truly is.”

A lot of the scenes in Spooks are filmed in public spaces in London such as train stations, underground stations and in the streets. How do people react to you and the others running through London with a film crew in tow?

“Most of the time we try to be as inconspicuous as possible which means working with long lenses so the cameras can be quite far away for the initial master shots, but can also punch in quite tight, rather like a surveillance camera. It’s a Spooks trademark and a focus-puller’s nightmare! But it gives us the chance to get two or three takes when no one realises that we are filming. I feel like the “real deal”, trying not to draw attention to myself and trying not to catch anybody’s eye.

“We often have to rehearse in another location and then walk out into a crowded area and just go for it. We work on hand signals from the First AD (assistant director) so they don’t call “action” really loudly. It’s great if something big is going to happen, like a fight, a chase or an arrest, because you get real reactions – of course, if guns are being used, or bomb threats depicted, we have to put up massive signs telling everyone we are filming! It makes me realise how fast London is; no one really hangs around.

“Most people see what we are doing but rarely have time to stop. I think Spooks really puts London on film in an edgy, contemporary way. Not just the iconic glamorous locations, but the urban and industrial side to London, which normally one tries to avoid but is a designer’s dream.”

Lucas has lots of tattoos. What do they represent and do you like them?

“I love them – it is a literal layer. Lucas has always had many layers and this year we go very deep into who he is. I love that his prison history has been etched onto his skin and they can be revealed to remind the audience that his past is cluttered with complications. Each one has a specific meaning from a specific period in his past.

“The most prominent is the William Blake picture, Urizen, on his chest. It depicts God as the architect and it is a reminder to Lucas he may not be able to control or construct his own destiny and that he will always be at the mercy of God. The tattoos also help me avoid the “gratuitous torso shot” as they take about two hours to put on, so “getting my kit off” has to be carefully planned!”