David Tennant and Tom Baker are uniting to battle the Daleks in an upcoming Doctor Who audio-drama. The longest-running sci-fi TV series in the world, Doctor Who has become a cult classic. Regeneration is the secret to the show's success. Doctor Who can reinvent itself periodically, recasting its star and allowing a new showrunner to take it in entirely new directions.

Every now and again, though, two or more incarnations of the Doctor come together in a fan-pleasing adventure in which they battle against iconic foes. The first multi-Doctor arc, "The Three Doctors," aired in 1972, uniting William Hartnell, Patrick Troughton, and Jon Pertwee, swiftly followed by 1983's "The Five Doctors." Since then they've become a mainstay in production terms, most notably with the celebrated simulcast of "The Day of the Doctor" featuring John Hurt, Matt Smith, and Tennant. But some of Doctor Who's biggest adventures take place away from the small screen, in audio-dramas produced by Big Finish; they've just announced their newest multi-Doctor event.

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According to Big Finish, Doctor Who: Out of Time 1 will release in August. It will feature Baker and Tennant, two of the most popular actors to ever play the central role of the Doctor. They're going up against their deadliest enemy, the Daleks. Here's the official summary from Big Finish:

The Cathedral of Contemplation is an enigma, existing outside time. It turns through history, opening its doors across the universe to offer solace to those in need.

Occasionally, the Doctor drops in – when he's avoiding his destiny, it’s an ideal place to get some perspective. Only, he's already there several lives earlier, so when dimension barriers break down, his past and present collide.

And when the Daleks invade and commandeer the Cathedral, two Doctors must unite to stop them – or face extermination twice over!

Doctor Who Out Of Time

This isn't the first Big Finish multi-Doctor story, but it is unique in that it unites a Doctor from the classic series with one from the 2005 relaunch. Baker is generally considered the iconic Doctor from classic Doctor Who, while Tennant is particularly beloved - and still missed - by fans of the new. Even better, it sounds as though this audio-drama is the beginning of something new for Big Finish. Their shop already contains slots for Out of Time 2 and 3, with story details and covers yet to be announced.

The coronavirus pandemic may have caused problems for most companies, but Big Finish has adapted admirably, allowing stars to record from home and then editing the recordings remotely. Indeed, they seem to have become only more ambitious of late, participating in an upcoming transmedia adventure called "The Time Lord Victorious" and now signing off on more multi-Doctor adventures. It will be quite some time before Doctor Who returns to the small screen. The Holiday Special had thankfully recorded before the pandemic, but it won't release until either Christmas or New Year's. Fortunately Big Finish is determined to ensure Doctor Who fans still get some delightful new adventures in the meantime.

More: The Most Exciting Doctor Who Story This Year... Won't Be On TV

Source: Big Finish