'Outnumbered' actress Claire Skinner and Bill Bailey are to guest-star in the 'Doctor Who' Christmas special.
The two stars will also be joined by 'Fast Show' actress Arabella Weir and comedian Alexander Armstrong in the festive episode with the Doctor, who is played by Matt Smith.
The storyline is set in World War II England and will see the Time Lord crash land his TARDIS in Dorset and pretend to be the caretaker of a creepy house where he will meet widow Madge Arwell - portrayed by Claire - and her two children, Lily ad Cyril.
The trio have been evacuated from London to the countryside to escape the German bombing raids and with the Doctor they embark on a wintery adventure partly inspired by C. S. Lewis' classic children's novel 'The Lion, The Witch and The Wardrobe'.
Claire said: "I am thrilled Madge is a bit of a super-mum. It's a magical part."
Showrunner Steven Moffat insists the Yule Tide story is the most "Christmassy" 'Doctor Who' episode yet.
He said: "If you thought last year's show was the most Christmassy ever then think again!
"The Doctor at Christmas - nothing is more fun to write. It's maybe because it's so his kind of day. Everything's bright and shiny, everybody's having a laugh, and nobody minds if you wear a really stupid hat. Of all the Doctors, Matt's is the one who was born for this time of year."
Production on the Christmas special has already begun in Cardiff and is scheduled to conclude in mid-October.
'Doctor Who' continues on BBC One this Saturday with 'Closing Time', which sees James Corden return as Craig Owens.