Written by Terrance Dicks and script edited by Robert Holmes, this four-part story was scheduled to be the opening serial of Season 15, featuring the Fourth Doctor and Leela investigating three sinister vampires who malevolently controlled a medieval Earth village and had far grander intentions than first appeared. The serial was ready to be made until the BBC decided that they didn't want "Doctor Who" to be doing a story about vampires at the same time that they were doing a dramatisation of Bram Stoker's "Count Dracula" starring Louis Jourdan in the title role. "The Vampire Mutations" was therefore replaced by "Horror of Fang Rock", also written by Terrance Dicks, after Robert Holmes told Dicks to write him a new story set on a lighthouse. "The Vampire Mutations" is a rarity among unmade "Doctor Who" serials in that its script was later changed, adapted and made into an actual televised serial for Season 18. Season 18's script editor, Christopher H. Bidmead, was looking through old scripts that had never been made for one reason or another and came across "The Vampire Mutations", liked the script more than the others and then contacted Dicks. Bidmead and Dicks then worked alongside each other to develop what became the Season 18 serial "State of Decay", with their ideas for the script often clashing.