"Black Alert" is the 980th episode of Casualty and the 19th episode of the 30th series. It was preceded by "Lie to Me" and followed by "Shame". It was directed by David Beauchamp and written by Matthew Barry, and will be the first episode since the two-part series premiere to feature all of the main cast members. In addition, Henrik Hanssen, portrayed by Guy Henry made another guest appearance in this episode.