Dr. Gwen Adshead is a leading psychiatrist and psychotherapist. Alongside her continuing work at Broadmoor Hospital as a Consultant Forensic Psychotherapist, where she runs psychotherapuetic groups for offenders, she also works in a medium secure unit in Hampshire. Her first trade book, The Devil You Know, was published by Faber & Faber in 2021 and was co-written with Eileen Horne. She has published a number of academic books and over one hundred papers. She was honoured with the President's Medal for services to psychiatry in 2013.

Eileen Horne is a writer and dramatist. She worked for twenty years as a television drama producer before gaining an MA in Creative and Life Writing from Goldsmiths College in 2012. She has been an editor, media lecturer and translator, and is the author of two non-fiction books and the scriptwriter of numerous BBC radio dramas.