After months of speculation as to what was going on in the former Bradford police headquarters on Centenary Square, the answer arrives this weekend in the form of hi-tech secret agent TV show Spooks: Code 9.

The drama, filmed at the Tyrls and in and around Bradford earlier this year, will premiere on BBC3 at 9pm this Sunday.

With the tag-line “For Queen… for country… for kicks” the series is a spin-off from the BBC’s popular MI5 drama Spooks.

Unlike the “parent” show, which stars Rupert Penry-Jones and Peter Firth, Spooks: Code 9 takes place in 2013, one year on from a terrorist nuclear attack which has destroyed London and relocated the UK capital to Manchester.

The Tyrls, formerly the Bradford police HQ, doubles as the nerve-centre for MI5 which is trying to keep order in a world teetering on anarchy.

Spooks: Code 9 stars Joanne Froggatt (of Coronation Street and Life on Mars fame) as an experienced agent who has to kick a team of unruly new recruits into shape.

Producer Chris Fry said: “After the bomb in London, MI5 needs more people on the ground immediately – not only to replace the officers they’ve lost, but to deal with the new challenges that face the nation.

“They’ve set up field offices in every major town and the plan is to have younger officers who are immersed and attuned to every potential threat.

“In the new MI5 it doesn’t matter where you come from. If you have ability and dedication they’ll have you on the streets within six months. And that’s where our team come in; they’re the new Field Office 19.”

The new recruits are played by Liam Boyle, Ruta Gedmintas, Andrew Knott and Georgia Moffett, who have all appeared in recent shows such as The Street, Life on Mars, Gavin and Stacey and Doctor Who.

The production team put the cast through their paces on a variety of locations around Bradford as well as in the Tyrls. In March a large area of Little Germany was closed off for a full day of filming, with the ISA office supplies building on Vicar Lane doubling as a bank. Shooting also took place near the NCP car park on Hall Ings and in Bradford city centre.

The series has been created by Kudos, the company behind Life on Mars, Ashes to Ashes and Spooks.

Watch out for an interview with Georgia Moffett, who plays Kylie, in Saturday’s Space supplement.