All is not well at the Wenley Moor underground atomic research station: there are unaccountable losses of power-output; nervous breakdowns amongst the staff; and then — a death!

UNIT is called in and the Brigadier is soon joined by Doctor Who and Liz Shaw in a tense and exciting adventure with subterranean reptile men — Silurians — and a 40 ft. high Tyrannosaurus rex, the biggest, most savage mammal which ever trod the earth!

Novelization of the Doctor Who TV series; seven episode story "The Silurians" (1970), script by Malcolm Hulke.