Mission of the Viyrans (audio story)

 was a single part story released along with The Mind's Eye, though unlike other releases this story is not connected to the story it is released with nor does it have the same cast as The Mind's Eye; this story does not feature Erimem played by Caroline Morris.

Publisher's summary
Mission of the Viyrans (A One-Part Story)

The Doctor and Peri take a holiday on the planet Gralista Social, but soon discover they aren't the only time-travelling aliens in town.

Cast

 * The Doctor - Peter Davison
 * Peri Brown - Nicola Bryant
 * Lawrence - Peter Sowerbutts
 * Chris - Philip Childs

Continuity
to be added

Timeline

 * Mission of the Viyrans occurs after BFA: The Bride of Peladon
 * Mission of the Viyrans occurs before BFA: The Judgement of Isskar