Earthfall (audio story)

 was the second story in the audio anthology, Extinction, produced by Big Finish Productions. It was written by Andrew Smith and featured Jemma Redgrave as Kate Stewart and Ingrid Oliver as Petronella Osgood.

Publisher's summary
Lieutenant Sam Bishop is finishing an assignment in Bangkok when he receives a call from Kate Stewart. She has a new job for him — hunt for a stray Nestene energy unit that has come down somewhere in the Gobi desert.

In Mongolia, Sam is joined by Osgood and they set off into the Gobi. But there are Autons in this desert. They are also looking for the energy unit, and they're ready to kill anyone who comes into contact with it.

Back in London, Kate is becoming suspicious of Simon Devlin's company, and decides to pay him a visit.

Plot
to be added

Cast

 * Kate Stewart - Jemma Redgrave
 * Osgood - Ingrid Oliver
 * Lieutenant Sam Bishop - Warren Brown
 * Captain Josh Carter - James Joyce
 * Simon Devlin - Steve John Shepherd
 * Jenna Gold - Karina Fernandez
 * Jacqui McGee - Tracy Wiles
 * The Nestene Consciousness - Nicholas Briggs

Continuity

 * Sam is aware of the Nestene's relationship with UNIT. (TV: Spearhead from Space, Terror of the Autons)
 * Kate gets nervous when sitting in a plastic chair. (TV: Terror of the Autons)