to be added
- Professor George Litefoot - Trevor Baxter
- Henry Gordon Jago - Christopher Benjamin
- Ellie Higson - Lisa Bowerman
- Percival Quick - Conrad Asquith
- Patsy - Flaminia Cinque
- Jeremiah Castle - Andrew Greenough
- Mulberry Gride - Robert Whitelock
- Jeremiah Castle, the self-proclaimed King of Jacob's Island, was hanged in the 1860s.
- As a child, Jago lived downwind of a tannery.
- Inspector Quick once saw an ostrich egg at a museum.
- Jago's aunt Maude used to take him swimming in Margate.
- By the 1890s, London is the most populous city on Earth.
- This story was primarily recorded on 17 October 2013 at The Moat Studios, with additional recording on 4 July and 7 July.
- Patsy was named after Patsy Smart, who played her in The Talons of Weng-Chiang.
- Jago refers to Arthur Conan Doyle, whom he and Litefoot had met in 1894. (AUDIO: The Monstrous Menagerie)
- In 1889, Patsy discovered Joseph Buller's body floating in the River Thames after he was killed by Mr Sin on the orders of Li H'sen Chang. (TV: The Talons of Weng-Chiang)
- Jago refers to his aunt Maude who lives in Margate. (AUDIO: The Spirit Trap)
- Jago, Litefoot and Patsy fell under the influence of the Darkling Façade when its amniotic fluid came into contact with them in Gride's warehouse. (AUDIO: Higson & Quick)