The creature then stalks and kills the others in the lighthouse. Vince dies first, then Adelaide. 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 the 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.