a BBC Cymru Wales Drama Production ; executive producers, Brian Minchin and Steven Moffat ; directed by Jamie Payne ; written by Steven Moffat ; produced by Marcus Wilson
Syfy original ; Jocko Productions ; Amblin Television ; Dark Horse Entertainment ; Universal Content Productions ; created for television by Chris Sheridan ; produced by Brian Leslie Parker ; written by Chris Sheridan ... [and others] ; directed by Robert Duncan McNeill ... [and others]