ADELAIDE: Lord Palmerdale is already a millionaire. All the advantage is with us. DOCTOR: He's been dead for hours. HARKER: Are you all right, man? Instead, I've locked it in, with us. It's just the old chap. LEELA: A waste of time. SKINSALE: Some men make me nervous when I'm with them. You see, in the space surrounding an electrically charged body there occurs an electric potential which is proportional to the charge Q, and inversely proportional to the distance R from the centre. [SCENE_BREAK]
ADELAIDE: But what was that ghastly scream? [SCENE_BREAK]
DOCTOR: Rigor mortis.
Plan: A: A death scream; Q: What is heard, yet all are accounted for? A: the Doctor; Q: Who finds a body stashed away but hours old? A: rigor mortis; Q: What is settling in on the body of the Doctor's companion? A: a chameleon; Q: What is the Doctor sure is in the lighthouse? A: the lighthouse; Q: What is the Doctor locked inside with the others? Summary: A death scream is heard, yet all are accounted for. Eventually the Doctor finds a body stashed away but hours old, with rigor mortis already settling in, which means there's a chameleon in their midst. Completely cut off from the rest of the world and with an escalating body count, the Doctor wonders just what, exactly, he's locked inside the lighthouse with them all.