The 2016 'Doctor Who' Christmas special will feature a comic-book superhero.
The Time Lord (Peter Capaldi) will team up with a mysterious caped crusader, whose real name is Grant (Justin Chatwin), and an investigative journalist, played by Charity Wakefield, to save New York from a deadly alien threat.
Justin, who has previously starred in 'Orphan Black' and 'War of the Worlds', said: "Working with the amazing people at 'Doctor Who' has been one of the most fun and rewarding projects I've ever had the pleasure of being involved with."
And Steven Moffat, Writer and Executive Producer, explained why he chose to feature a superhero on the show.
He said: "I've always loved superheroes and this Christmas Doctor Who dives into that world. My favourite superhero is Clark Kent. Not Superman, Clark Kent."
Matt Lucas will also star in the special, along with Adetomiwa Edun, Aleksandar Jovanovic and Logan Hoffman.
The 60 minute 'Doctor Who' Christmas special will air on BBC One on Christmas Day (25.12.16) and has been written by Steven Moffat, executive produced by Brian Minchin, and produced by Peter Bennett.
Ed Bazalgette directed the episode, which was shot in Cardiff at BBC Wales Roath Lock Studios.
Meanwhile, departing showrunner Steven is keeping details of the Time Lord's new assistant Bill (Pearl Mackie) under wraps.
Speaking at New York Comic Con, he said: "I'm not going to say anything about 'Bill,' but you will discover her character and how she came to meet the Doctor when the show comes back."