Last night's new Doctor Who episode, The Girl Who Lived, marked the debut of guest star Maisie Williams as Ashildr. The Girl Who Lived was the first entry of a two-part episode, with the actress returning for next week's The Woman Who Lived, airing Saturday, October 24 on BBC and BBC America. Today, BBC revealed two new trailers for The Woman Who Lived, featuring Maisie Williams and series star Peter Capaldi.

The Woman Who Lived is set in 1651 England, where the deadly Highwayman 'The Knightmare' and his sidekick stalk the dark streets of London. But when they find loot that's not of this world, they come face to face with The Doctor. Who is the Knightmare in league with? And can the Doctor avoid the hangman's noose and protect Earth from a devilish betrayal? Rufus Hound and Todd Kramer also guest star in next week's new episode.

The previous episode, The Girl Who Lived centered on the Doctor (Peter Capaldi) and Clara (Jenna Coleman), who have been captured by Vikings. The Time Lord and his companion step up to help protect their village from Space Warriors from the future, known as the Mire. Outnumbered and outgunned, their fate seems inevitable. So why is the Doctor preoccupied with a single Viking girl? Presumably, Maisie Williams' Ashildr is this "single Viking girl," who seems to play a big part in The Woman Who Lived as well.

Related: Doctor Who Showrunner Steven Moffat Leaving After Season 10

Other confirmed guest stars for Season 9 include Rebecca Front, Rufus Hound, Paul Kaye, Joivan Wade and Sophie Stone. The show's ninth season has been written by lead writer Steven Moffat, Toby Whithouse, Jamie Mathieson, Peter Harness, Mark Gatiss and new writers to Doctor Who, Sarah Dollard and Catherine Tregenna. This season will be directed by Hettie Macdonald, Daniel O'Hara, Edward Bazalgette, Daniel Nettheim, Justin Molotnikov, Rachel Talalay, and produced by Tracie Simpson, Derek Ritchie, Nikki Wilson and Peter Bennett.

Maisie Williams will of course be back as Arya Stark in Season 6 of Game of Thrones, which will debut sometime next spring on HBO. Until Game of Thrones comes back, though you can take a look at new footage from Doctor Who. As we approach the halfway mark of Doctor Who Season 9, what do you think about these new episodes so far?