Mirror, mirror, on the wall… Who’s the scariest space alien of them all? Get ready to find out during this spooky Doctor Who marathon!

The latest season of Doctor Who debuts its first episode, “Halloween Apocalypse”, on (you guessed it) October 31. And to really set the mood, BBC America will air over 100 hours of Doctor Who leading up to the premiere, with special highlights on the scariest episodes!

The marathon kicks off today with six episodes from David Tennant’s run, including fan favorites like “Blink” and “Forest of the Dead.” Then tune in October 29 for Matt Smith’s “The God Complex”, plus Peter Capaldi’s “Listen” and “Heaven Sent.” Finally, slide into the Jodie Whittaker era on October 30 with “The Haunting of Villa Diodati” and more to gear up for Flux.

Doctor Who: Flux “Chapter One: The Halloween Apocalypse” kicks off a universe-spanning final adventure for Whittaker’s Thirteenth Doctor. 

On Halloween, all across the universe, terrifying forces are stirring. From the Arctic Circle to deep space, an ancient evil is breaking free. Meanwhile, in present day Liverpool, the life of Dan Lewis is about to change forever. Why is the Doctor on the trail of the fearsome Karvanista? And what is the Flux?

In contrast to Doctor Who’s usual structure, the six episodes of Flux represent one overarching story. From Liverpool to the depths of space, via the Crimean war and a planet named Atropos which shouldn’t even exist, fighting old foes and new creatures from beyond our dimension, the Doctor and company face a race against (and through!) time to uncover a universe-spanning mystery: what is the Flux? The previews for the new season have teased the return of familiar villains, including Sontarans and the Weeping Angels. We’ll also see Game of Thrones’ Jacob Anderson take on an important season role as Vinder, and John Bishop as new companion Dan.

So, are you excited to kick off Flux with Halloween Apocalypse? Which scary Doctor Who episodes are your favorites? Let us know in the comments below.