Jodie Whittaker will be joined by her regular team of assistants for Doctor Who's New Year's special – as well as a trio of brand-new co-stars.
The BBC has confirmed that Charlotte Ritchie will play a character called Lin, Nikesh Patel will play Mitch and Daniel Adegboyega will star as Aaron.
But their character names are all that's been revealed for now.
You'll probably otherwise know Charlotte Ritchie as Barbara Gilbert (later Hereward) from Call the Midwife. She also played Oregon in Fresh Meat and Hannah in Siblings.
Alongside Jodie's Doctor, Tosin Cole (Ryan), Bradley Walsh (Graham) and Mandip Gill (Yaz) will all be appearing in the festive instalment.
Written by showrunner Chris Chibnall and directed by Wayne Yip, the hour-long episode will see the Doctor, Ryan, Yaz and Graham arrive home – only to come across a new alien threat to planet Earth.
"We're thrilled to be starting the New Year with a bang on BBC One, as Jodie Whittaker's Doctor and friends face a terrifying alien threat in an action-packed, hour-long special adventure for all the family," Chibnall said.
BBC's director of content Charlotte Moore added: "We're delighted the Doctor and her companions will be welcoming BBC One audiences into 2019 with this exciting new episode. The Doctor's fans are in for a special treat on the first day of the new year."
Doctor Who's New Year's special will air on January 1 on BBC One. The Doctor Who series 11 finale 'The Battle of Ranskoor Av Kolos' airs this Sunday, December 9 at 6.25pm.
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