Former travelling companion to The Sixth and Seventh Doctors, Melanie Bush (star of stage, screen, audio etc Bonnie Langford) will now be joining Chuti Gatwa's Doctor in the next series.
After her brief cameo in the final episode of Jodie Whittaker's jaunt in the TARDIS, the specific details of Mel's return to the show are being kept mum by showunner Russell T Davies.
All he would say was:
"Open those TARDIS doors wide, because Bonnie’s back! What an honour, delight and hoot to welcome back the character of Melanie, after too long away. And this isn’t just a cameo, Bonnie is right in the thick of the action, battling monsters and chaos and cliffhangers, right at the Doctor's side, just like the old days."