Doctor Who can be funny, scary, creepy, silly, thought-provoking, joyous, heartbreaking, and everything in between, but every now and then we get an episode that’s really sort of mind-bending. Judging from the TV spot and clip below, this week’s episode may be one of those.

Listen
Season 8 | Episode 4 | Original Airdate: September 13th, 2014 | 9:00PM
When ghosts of past and future crowd into their lives, the Doctor and Clara are thrown into an adventure that takes them to the very end of the universe.

What happens when the Doctor is alone? And what scares the grand old man of Time and Space? Listen!

Written by Steven Moffat. Directed by Douglas Mackinnon.

TV Spot: Doctor Who – 804 Listen

Clip: Doctor Who – 804 Sneak Peak: Not Alone

See?!

Doctor Who, starring Peter Capaldi, Jenna Coleman, and Samuel Anderson, airs Saturdays at 9/8c on BBC America.