May 5, 2017 Series 10: Knock Knock – Introductions & Clips Doctor Who, News Share on X (Twitter) Share on Facebook Share on Reddit Share on WhatsApp Share on E-mailSteven Moffat introduces the episode: Watch this video on YouTube Peter & Pearl introduce the episode: Watch this video on YouTube Clip: Watch this video on YouTube Clip 2: Watch this video on YouTube Please Support DWTV