The continuing adventures of Henry Gordon Jago and George Litefoot, characters first introduced on television in Doctor Who: The Talons of Weng-Chiang (1977), who have become Infernal Investigators, solving mysteries involving paranormal or alien phenomena in 1880s London.

This release features four full-cast audio dramas plus a behind-the-scenes documentary:

1.1 'The Bloodless Soldier', written by Justin Richards and directed by Lisa Bowerman. Featuring Alex Lowe, John Banks, Robin Bowerman and Alex Mallinson. A group of soldiers return from overseas service - but they have brought a terrible evil back with them. As death strikes on the streets of London, Sergeant Quick calls upon the help of Professor Litefoot while an old enemy lurks in the shadows.

1.2 'The Bellova Devil', written by Alan Barnes and directed by Lisa Bowerman. Featuring Stephen Thorne, Duncan Wisbey and Alex Mallinson. A body is found on the Circle Line wearing full dress uniform. It is identified as Reginald Colville - a man who was certified dead some six weeks ago! In an attempt to solve the mystery, Jago and Litefoot become unwilling bodysnatchers....

1.3 'The Spirit Trap', written by Jonathan Morris and directed by John Ainsworth. Featuring Janet Henfrey and Lex Shrapnel. Ellie Higson believes that spiritualist Mrs Vanguard can hear the voices of the dead, but Henry Gordon Jago thinks it's all superstition and theatrical trickery. But if Vanguard is a harmless fake, then why have some of those who have attended her seances disappeared so mysteriously?

1.4 'The Similarity Engine', written by Andy Lane and directed by Lisa Bowerman. When Jago takes a tumble on an unseasonably icy road, he ends up in hospital. But this is no ordinary medical establishment, and the patients are suffering from no ordinary illnesses. At last, the fiendish scheme of Dr Tulp is drawing to its cataclysmic climax.