Big Finish
Jevvan (voice)

Welcome to Valhalla, Capital of Callisto, Jupiter's premier moon, where anything and everything is up for sale. But Valhalla isn't quite what it says in the brochures – not since Earth granted independence and cut off the supplies. The former Doctor (FOR SALE. EXCELLENT CONDITION) visits the Job Centre and finds power cuts, barcoded citizens and monthly riots (ALL BOOKABLE). And then there's the problem with the termites…

Jevvan (Michelle Gomez) is an engineer who ends up helping the Doctor (Sylvester McCoy).