reappears a changed man, which the others put down to shock. Palmerdale is killed in the lamp room by a glowing alien presence on the outside of the lighthouse, and then Harker is killed in the boiler room. From the alien light emanating from Reuben, it is clear he has become possessed or transformed by the alien creature. The Doctor finds Harker's body and then Reuben's own – the latter cold for some time – which means the creature in Reuben's form has chameleonic properties. The creature then stalks and kills the others in the lighthouse. With its presence now revealed, the alien sheds its disguise, revealing it to be a Rutan, a green blob-like amphibious life form, whose scout ship crash-landed in the sea and is trying to summon its mother ship. With the Rutans losing a long war against their hereditary enemies, the Sontarans, they plan to turn the strategically-located Earth into a base, from which they can launch a counterattack. However, once the Sontarans find the planet, they will certainly bombard Earth with photonic missiles, taking countless human lives in the process. The Doctor uses a flashbomb to disorient the Rutan, forcing it to retreat to the boiler room. The Doctor and Skinsale retrieve diamonds from Palmerdale's body belt to use in modifying the lighthouse beacon, but Skinsale is killed by the Rutan in the process. The Doctor then modifies a flare mortar to destroy the alien, and then uses the diamonds as a focus for the electric lighthouse beam to convert it into a high-energy laser, with which he destroys the Rutan mothership. Disobeying the Doctor, Leela watches the laser destroy the ship and is momentarily blinded, and as a side effect, the blinding flash turns Leela's eyes from brown to blue. The Doctor quotes Wilfrid Wilson Gibson's poem Flannan Isle as they leave. Production Working titles for this story included The Monster of Fang Rock and The Beast of Fang Rock. Horror of Fang Rock was a late replacement for the scripts Terrance Dicks had originally submitted, a vampire-based tale entitled The Vampire Mutations, which was cancelled close to production as it was feared it could detract from the BBC's Count Dracula, a high-profile adaptation of Bram Stoker's classic novel Dracula, which was due for transmission close to when the serial would have aired. A re-written version did, however, eventually see production in 1980 as