The KVI. Outside the Kremlin, beyond the President. A secret institute created by his majesty Tsar Nicholas II to defend the Motherland from unknowable evil. The 20th Century changed everything – but the KVI are still ready...

Based on the beloved Doctor Who spin-off series created by Russell T Davies, Big Finish's range of Torchwood audios continues the legacy of Earth's greatest defenders, with new stories set in and around the original TV show.

The next in our second series of audio dramas, Torchwood: Zone 10 sees the return of Naoko Mori as Toshiko Sato – and chronicles her voyage to the wastelands of Russia to uncover a deadly alien threat...

They call it "Pulse" - a radio signal which has puzzled the world for 40 years. But now Toshiko Sato has solved it.

She's uncovered a message which leads her to Russia, and into an uneasy alliance with the KVI - the Russian equivalent of Torchwood. Toshiko needs to get into Zone 10 - a frozen wasteland which officially doesn't exist.

An intergalactic war was once fought in Zone 10. And it turns out there's a survivor.

Written by David Llewellyn, and starring Naoko Mori, Krystian Godlewski, Ella Garland and Geoffrey Breton, Torchwood: Zone 10 is available to buy and download today, introducing powerful new players into the Torchwood mythology – and a danger that will plague the team for years to come...

You can also subscribe to Torchwood Series 2 at an additional saving, with CD subscriptions unlocking complementary digital downloads, available as soon as a title is released. Series 1 is also available in a single money-saving bundle.

Torchwood continues next month with the return of Tom Price as Sergeant Andy in Torchwood: Ghost Mission.

Keep an eye on the Big Finish website throughout April for more details from Torchwood: Series 2.