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
HBO Entertainment in association with the BBC ; producer, Todd London ; executive producers, William J. MacDonald, John Milius, Anne Thomopoulos, John Melfi, Bruno Heller ; created by John Milius and William J. MacDonald and Bruno Heller
BBC ; 2 entertain ; devised by Bill Gallagher ; directors, Sue Tully and Patrick Lau ; writers, Bill Gallagher and Rachel Bennette ; producer, Ann Tricklebank