Set in 1936 and 1937, it originally followed the exploits of DI Lionheart and ghost-story writer Professor Edward Dunning, as played by Nicholas Courtney and Terry Molloy.
The fourth story "The Curse of the Black Comet", guest-starring Brian Blessed, was released in 2009 and broadcast in 2010.
The fifth story, "The Secret Weapon of Doom", guest-starring Leslie Phillips and Nigel Havers, was released in 2010 and broadcast on BBC Radio 4 Extra in early 2012.
[citation needed] In 2011, after the death of actor Nicholas Courtney, it was announced that David Warner would be joining the series.
The seventh Scarifyers story, "The Horror of Loch Ness", was released in June 2012 and features the final performance of Philip Madoc.