Richard Neville and Julie Clarke’s On the Trail of the Serpent: the Life and Crimes of Charles Sobhraj was first published in 1979 and narrates events from the killer’s childhood until the late 1970s. It became a global bestseller on its initial publication, and in 1989, inspired a television film about Sobhraj’s crimes. Compelling and well-researched, it paints a chilling picture of a scheming yet charismatic individual who took the lives of young travellers, apparently without remorse. Much of Neville and Clarke’s account is drawn from interviews the pair conducted with Sobhraj in 1977, enabling them to delve into his early life, first marriage and convictions in France. Those areas were largely left out of the BBC-Netflix series, which focuses instead on the thefts and murders Sobhraj committed from 1975 to 1976 on travels through Hong Kong, Singapore, Thailand, India and Nepal, often using passports stolen from his victims. The series also chooses to foreground the lengthy investigation into Sobhraj by Dutch diplomat Herman Knippenberg and his wife, German diplomat Angela Kane. A new edition of Neville and Clarke’s book was published by Vintage in December 2020 to tie in with the series’ UK release on BBC One. Richard Neville, an Australian journalist known for editing British counter-culture magazine Oz in the 1960s and 1970s, had passed away in 2016, and new revisions were made by Clarke, Neville’s co-author and wife. The complicated history of Charles Sobhraj’s many crimes had undergone several developments since the first publication, and Clarke’s new additions were able to provide some answers to questions left unanswered in the original. That was confirmed at the December 2020 BBC press launch for The Serpent, when writer Richard Warlow (Ripper Street, Waking the Dead) and director Tom Shankland (Les Misérables, The City and the City) cited the book as inspiration for their series. Shankland had originally learned about Sobhraj while on his own experiences travelling in South Asia, where the hippie-targeting serial killer had become a kind of campfire ghost story for young travellers. The director approached Warlow with the story, and Neville and Clarke’s book became a key resource for their production. If The Serpent leaves you with questions, or wanting to fill gaps in the life of Charles Sobhraj and his victims, then The Trail of the Serpent is your next port of call. The Serpent is streaming now on Netflix.