by Jonathan Morris
The TARDIS is going underground. When the Doctor and Romana find themselves buried beneath the surface of an alien world, they're soon swallowed up by a giant burrowing machine. This is where the inhabitants of this planet live - in huge, constantly moving, Drill-towns, chewing up the fuel and resources of the planet in order to survive.
But something else lurks in the earth. Something that feeds on the Drill-towns. Something that is relentless and will not stop.
The Silex are hunting.
Tom Baker (The Doctor), Lalla Ward (Romana), Matthew Cottle (Mr Maxwell Wilberforce Bell), Abigail McKern (Mrs Lucretia Bell), Robbie Stevens (Mr Jelicho Wigg / Mr Wilfer Wagstaff), Jane Slavin (Miss Arabella Wagstaff / Mrs Betsy Wagstaff), John Banks (Silex / Mr Stoker)
Directed by Nicholas Briggs
*Featuring the Fourth Doctor and the Second Romana
*A Big Finish audio production