More information is trickling through about the planned Doctor Who spin-offs, one of which is set to feature Jemma Redgrave.

The spin-off – part of the expanded Whoverse under second-time showrunner Russell T Davies’ deal with Disney+ – will reportedly be based on military research organisation UNIT and will star Redgrave as Kate Stewart. Redgrave has played Stewart since 2012 in 10 previous episodes of Doctor Who, and the spin-off series will focus on her running UNIT.

UNIT – which stands for Unified Intelligence Taskforce – was first introduced in 1968 under second Doctor Patrick Troughton. The organisation, which investigates paranormal and extraterrestrial threats to Earth, got a fleeting mention in 2005, post-reboot, before recurring under David Tennant, Matt Smith, Peter Capaldi, and Jodie Whittaker’s runs.

In a recent interview with GQ, Davies explained he aims to take Doctor Who to the “next stage” with these spin-offs series. Redgrave will appear in the series Christmas special this year alongside new Doctor Ncuti Gatwa, before launching the offshoot series. Series veterans David Tennant and Catherine Tate are also due to feature in three of the 60th anniversary specials.

Per The Mirror, which broke the news of Redgrave’s starring role, a monsters spin-off is also planned, though no further details have emerged.