If you're feeling busy this Christmas Eve, spare a thought for the Doctor in precisely 2044 years' time... and 2074 years' time: he has a planet to save twice over!

For the next seven days, the download of Doctor Who - Flip-Flop is available for free, a full-cast Doctor Who story written by Jonathan Morris and starring Sylvester McCoy and Bonnie Langford:

Christmas Eve in the year 3060, and the planet Puxatornee is home to a prosperous human colony.

A space craft has arrived in orbit carrying the Slithergees, a race of obsequious alien slugs. Their home world has been destroyed and they are humbly requesting permission to settle on the first moon.

And if they don't get permission, then they are humbly threatening to declare all-out war. The future hangs in the balance. The decision rests with Bailey, the colony' s president - but she has other things on her mind.

Christmas Eve in the year 3090, and the planet Puxatornee has changed beyond all recognition.

The Doctor and Mel arrive, on a completely unrelated mission to defeat a race of terrible monsters, and soon discover that something rather confusing has been happening to history.

Flip-Flop is a unique innovation in storytelling. A Doctor Who adventure originally told over two CDs, one black, one white - where the Downloads can be listened to in either order.

To get your copy, use the offer code of "flipflop" when visiting here: Flip Flop Offer.

Doctor Who - Flip-Flop is free until midnight 31/12/2016 (UK time), when it goes back to the £2.99 price of the first 50 download-only titles.

Check out the range here for a choice of bundles and subscriptions covering these stories.

Meanwhile, a reminder that:

And a Merry Christmas to all of you at home!