The First Son (audio story)

 was the first story in the audio anthology Dalek Universe 3, produced by Big Finish Productions. It was written by Lizzie Hopley and featured David Tennant as the Tenth Doctor, Jane Slavin as Anya Kingdom and Alex Kingston as River Song.

Publisher's summary
The Doctor's attempts to return home have led him to the middle of a war zone... and a familiar voice.

The travellers have arrived on a planet made up of crashed space-ships where they encounter River Song... Or do they? Because she's dressed as a Movellan and claims to be a member of that robot race. Is she undercover, a duplicate, or something more sinister?

And more importantly... who is her son?

Plot
to be added

Cast

 * The Doctor - David Tennant
 * Anya Kingdom - Jane Slavin
 * River Song - Alex Kingston
 * The Daleks - Nicholas Briggs
 * Rodekka - Noma Dumezweni
 * Kamen Vers - Matthew Jacobs-Morgan
 * Karl Lamb - Paul Panting

Worldbuilding

 * The Doctor says "mto" is Swahili for "river".

Continuity

 * The Doctor is still anxious for Anya's safety. (AUDIO: The Lost)
 * Anya recalls meeting River as the queen of the Mechonoids. (AUDIO: Queen of the Mechonoids)
 * The Doctor is aware of the inherent weakness behind the Movellan power packs. (TV: Destiny of the Daleks)
 * The use of implantation to monitor communications echoes a similar tactic employed by the Cybermen in AUDIO: Real Time.