DoctorDoctor Who Guide
Last updated 17 May 2017

Knock Knock

Series Episode Number: 831

World Premiere: Sat 6 May 2017 - 7:20pm BST [BBC One] (United Kingdom)
First Broadcast: Sat 6 May 2017 - 9:00pm EDT [BBC America]
Running Time: 45 minutes

5.73 Million (UK)

Appreciation Index: 83 (UK)

Audience Share: 24.9%(i) (UK)
Chart Position: 21(i) (BARB Week Top 30 Chart) (UK)

Bill is moving in with some friends and they’ve found the perfect house - so what if it’s strangely cheap to rent, and the landlord is a little creepy?

The wind blows, the floorboards creak, and the Doctor thinks something is very wrong. What lurks in the strange tower at the heart of the building - and why can’t they find any way to enter it?

The episode was also available with a special binarual version.