Here's a spoiler-filled preview of tonight's new episode of Doctor Who on BBC One.
Over 4 million viewers tuned in to last week's latest episode and tonight the tenth series continues with new episode Thin Ice, written by Sarah Dollard and directed by Bill Anderson.
The Doctor (Peter Capaldi) will be joined once again by new companion Bill (Pearl Macki) and Nardole (Matt Lucas).
In Regency England, beneath the frozen Thames, something is stirring.
The Doctor and Bill arrive at the last of the great frost fairs, and find themselves investigating a string of impossible disappearances - people have been vanishing on the ice!
Bill is about to discover that the past is more like her world than she expected, and that not all monsters come from outer space...
Doctor Who airs tonight at 7:20PM on BBC One.
This year's run is Peter Capaldi's last as the Doctor, previously announcing he would be stepping down after this year's Christmas special.
Capaldi first stepped into the TARDIS in 2013, and will leave the iconic role in the 2017 Christmas special after three incredible series of the BBC's global hit sci-fi drama.
Peter Capaldi said ahead of the current run: "One of the greatest privileges of being Doctor Who is to see the world at its best.
"From our brilliant crew and creative team working for the best broadcaster on the planet, to the viewers and fans whose endless creativity, generosity and inclusiveness points to a brighter future ahead. I can’t thank everyone enough. It’s been cosmic."
Peter Capaldi's final series also marks writer and executive producer Steven Moffat's last.
He said: "Like Peter, I’m facing up to leaving the best job I’ll ever have, but knowing I do so in the company of the best, and kindest and cleverest of men, makes the saddest of endings a little sweeter. But hey, it’s a long way from over.
"Peters’ amazing, fiery, turbulent Doctor is still fighting the good fight, and his greatest adventures are yet to come. Monsters of the universe, be on your guard - Capaldi’s not done with you yet!”