The Fourth Doctor Adventures: Series 10: Volume 1

 was a full cast audio anthology released on January 2021 by Big Finish Productions. It featured the Fourth Doctor and Leela.

Publisher's summary
The World Traders by Guy Adams

When a day out in 21st Century London leads to the TARDIS being impounded, the Doctor and Leela find themselves getting involved with the mysterious Amapan Investments, a company that’s managed to become remarkably successful in a remarkably short amount of time.

So what’s their secret? The Doctor and Leela are about to find out.

The Usurians have come to Earth. And they have big plans.

The Day of the Comet by Jonathan Morris

The TARDIS brings the Doctor and Leela to the ruins of a once-great city racked by earthquakes, where they find a giant rocket on the side of a mountain. The planet is due to be destroyed by a comet in a year’s time and this ship is the only way off world.

But is everything quite as it seems? At least one person in the city thinks the comet is going to come to obliterate the planet much sooner than people believe.

Which would be bad enough - if there wasn’t a far worse secret hidden behind the scenes...

Featured actors

 * Tom Baker
 * Louise Jameson