The Third Doctor Adventures (audio anthology)

 was a full cast audio anthology released in 2015 by Big Finish Productions.

Publisher's summary
This release comes as two new Third Doctor stories and a disc of extras:

Prisoners of the Lake (by Justin Richards)

Captain Mike Yates is investigating the disappearance of artefacts from an archaeological site deep below Dunstanton Lake. It’s hardly a job for UNIT. But when the team discover a mysterious ancient structure buried deep underwater, all that changes. When chief archaeologist Freda Mattingly ventures inside, she soon realises that her skills do not begin to equip her to deal with what she finds. As an ancient menace begins to stir the Doctor, Jo Grant and Mike Yates must dive down to the lake bed and discover the secrets hidden there. Secrets that could mean the end of all life on Earth… The Havoc of Empires (by Andy Lane)

The Doctor and Jo take Mike Yates on his first trip in the TARDIS, but instead of the historical cricket match they were aiming for they end up on a futuristic space station in the middle of a diplomatic crisis that might escalate into galactic war.

The alien leader of the Chalnoth Hegemony is marrying the human Director of the Teklarn Incorporation, but there are forces that will stop at nothing to disrupt the ceremony. The Doctor is accused of murder while explosions occur across the station, and only Jo Grant, pretending to be a security consultant, can save the day.

But then, there’s the Eels to consider…

Stories

 * Prisoners of the Lake
 * The Havoc of Empires