File:Steven Moffat Introduces Knock Knock - Doctor Who Series 10

Description
Steven Moffat delivers a disconcerting introduction to this terrifying episode.

Subscribe for more exclusive Doctor Who clips and content: http://www.youtube.com/subscription_center?add_user=doctorwho

http://www.doctorwho.tv http://www.youtube.com/user/doctorwho https://www.facebook.com/doctorwho https://twitter.com/bbcdoctorwho

Want to share your views with the team behind Doctor Who and win prizes? Join our fan panel here: https://tinyurl.com/YouTube-DoctorWho-FanPanel

This is a channel from BBC Worldwide who help fund new BBC programmes.