The Third Doctor Adventures: Volume 2

 was a full cast audio anthology released in 2016 by Big Finish Productions.

Publisher's summary
2.1 The Transcendence of Ephros by Guy Adams


 * The Doctor and Jo arrive on the dying planet Ephros, where Galactux Power Inc is exploiting the world's remaining resources. But something is stirring beneath the surface...

2.2 The Hidden Realm by David Llewellyn


 * The Doctor and Jo journey to Bramfield New Town when the husband of Jo's cousin vanishes mysteriously. As magpies circle overheard, the Doctor discovers a terrifying alien plot...