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...
| Sound | Dudley Simpson | Original Music Composer |
| Writing | Bob Baker | Writer |
| Directing | Lennie Mayne | Director |
| Writing | Dave Martin | Writer |
| Production | Philip Hinchcliffe | Producer |
| Writing | Robert Holmes | Script Editor |
| Editing | Christopher Rowlands | Editor |
| Production | Marion McDougall | Production Assistant |
| Crew | Dick Mills | Special Sound Effects |
| Costume & Make-Up | Judy Neame | Makeup Artist |
| Crew | Max Faulkner | Stunt Coordinator |
| Sound | Brian Hiles | Sound |
| Lighting | Derek Slee | Lighting Director |
| Camera | Max Samett | Camera Operator |
| Art | Christine Ruscoe | Production Design |
| Costume & Make-Up | Barbara Lane | Costume Design |
| Sound | Graham Bedwell | Sound |
| Visual Effects | Colin Mapson | Visual Effects Designer |
