When the TARDIS lands in a quarry on Earth, Sarah unearths what appears to be a fossilised hand, buried in one-hundred-fifty-million-year-old strata. Analysis shows the hand to be silicon-based and inert, but when Sarah begins to act as if possessed, the Doctor suspects that it may still be alive...

Science Fiction, Drama, Adventure

Tom Baker, Elisabeth Sladen, Stephen Thorne, Judith Paris, Roy Pattison, Roy Skelton