After first appearing in Doctor Who: The Shadow Heart, Vienna Salvatori (played by Star Trek: Deep Space Nine star Chase Masterson) landed her own spin-off series, starting with The Memory Box.

Berkeley Silver, one of the richest men in the Earth empire, lies dead in the Penthouse Suite of the Galileo space-hotel. Law Enforcement Officers Detective Captain McGinnis and Detective Sergeant Mead are called in to investigate – but it seems to have been the perfect crime. Even when subjected to a memory scan, everybody in the space-hotel has an alibi for the murder.

Which means it can only have been the work of one woman. The most accomplished – and the most glamorous – bounty hunter in the galaxy. Her name is Vienna Salvatori. And she has a little rule; nobody gets to hear her name and live...

For this month only, Vienna: The Memory Box is available for £2.99 on download and we'd like to hear what you made/make of it! You can chat about the story on the forums or on our Big Finish Facebook page, and you can learn more about it in this month's Listen Again in the new issue of our free downloadable magazine, Vortex.