Jenna Coleman will switch from starring as the long-reining British sovereign in “Victoria” to play Marie-Andrée Leclerc, the partner and accomplice of French serial killer Charles Sobrhaj, in the BBC and Netflix drama “The Serpent.” Coleman will star alongside the previously announced Tahar Rahim, who plays Sobrhaj, as well as Ellie Bamber and Billy Howle, who have joined the series.

Sobhraj was the chief suspect in the unsolved murders of up to 20 young travelers across India, Thailand, and Nepal’s hippie trail in the mid-1970s. Having slipped repeatedly from the grasp of authorities worldwide, he became Interpol’s most wanted man.

Howle will play Herman Knippenberg, a junior diplomat at the Dutch Embassy in Bangkok who unwittingly walks into Sobhraj’s web of crime and ultimately seeks to bring him to justice. Bamber will appear as his wife, Angela.

The BBC will launch the series in the U.K. Netflix will carry it in the U.S. and the rest of the world. ITV-owned indie Mammoth Screen is producing. Tom Shankland and Hans Herbots direct from Richard Warlow and Toby Finlay’s script. The show is filming on location in Thailand.

“‘The Serpent’ intoxicated me into the dark seductive world of Charles Sobhraj,” Coleman said. “I’m so looking forward to delving into hippie-trail depths and bringing to life this unfathomable real life story alongside Tahar, Billy, Ellie, Tom, Richard and the wonderful cast and production team for the BBC and Netflix.”