BBC One and Netflix’s The Serpent is inspired by the true story of how Charles Sobhraj (Tahar Rahim) – a serial killer and conman who murdered and robbed at least 12 Western tourists along the so-called ‘hippie trail’ in the 1970s – was brought to justice.

It also, though, takes a closer look at how he managed to bully and manipulate Marie-Andrée Leclerc (Jenna Coleman) into becoming not just his lover, but his accomplice, too.

As you will no doubt recall from the chilling first episode of the true crime series, the immaculately-dressed Marie-Andrée – despite appearances – dropped more than a few subtle hints that she was unhappy with her life at her lover’s side.

“I came for a holiday,” she tells someone when they ask how she wound up with Sobhraj.

“I did not [go home]. He made it impossible for me.”

In this episode of the addictive TV show, though, we’re taken back to the very beginning of their relationship. When a young Marie-Andrée – a legal secretary from a small town (or at least what she perceived as a small life) in French-speaking Quebec, Canada – meets Sobhraj while on holiday in India.

“[She] left the drabbest of upbringings in suburban Quebec to find a love that both transformed and cursed her,” explains show writer Richard Warlow.

“I want our audience to find Sobhraj the way others found him. Through Herman who, by the discovery of the man’s acts, knew him for what he was, through Marie-Andrée who saw him as the answer to the dead-end her life had become… And through all those others whose journeys across the nexus points of the hippie trail tragically intersected with a killer so cruelly expert in identifying their needs…

“Be it for a bed and a hot shower, rare gems, acceptance or love – Sobhraj saw those needs and then presented himself as the cure.”

Believing Sobhraj  to be an acclaimed war photographer, Marie-Andrée is flattered when he begins paying her attention. And so, when he sends her a string of letters begging her to leave Canada and her boyfriend for him (“Fly to Bangkok and be mine”), she decides to take a leap of faith for love.

When she arrives in Thailand, though, she doesn’t receive the warm, romantic welcome she had been hoping for. Instead, Sobhraj all but ignores her – to the point that she describes his lack of intimacy as “torment” in her diary. 

As such, the emotional abuser pushes her to the brink of despair, in an apparent bid to test the depth of her feelings for him. He is far from disappointed: the sheltered young woman doesn’t return home to her “sad” life in Canada, despite all he puts her through. 

In the process, she finds herself cut off from her friends, her family, and her “sanctimonious” parents. And thus her world becomes smaller, making Sobhraj’s role within it far larger and more influential than it has any right to be.

It is at this point that Sobhraj begins the next step in his tried-and-tested cycle of abuse: he love bombs her.

For those who aren’t familiar with the term, love bombing is a dating term used when someone begins overwhelming another person with compliments, gifts, and time in order to win over their trust. 

In doing so, a love bomber hopes to convince the perceived object of their affections to commit, so that they can manipulate them. 

“Love bombing will typically come to an abrupt end when the ‘wooing’ phase ends and the person knows that you really like them; because the chase is over they may suddenly lose all attraction to you, and drop you without explanation,” dating expert Hayley Quinn previously explained to Stylist.

So it goes in The Serpent: Sohraj lavishes Marie-Andrée with attention. He buys her a string of expensive presents, including a gorgeous puppy. And he promises, too, to whisk her away on a luxurious holiday.

Instead, he drugs and robs an Australian couple. And Coleman’s character, despite her initial shock, helps Sohraj to get away with his crimes.

To Sohraj, this is proof of Marie-Andrée’s love for him. And so, when they return to Bangkok, he allows her to move in with him.

“Everything I ever wanted, I had to take it,” he tells her. 

Despite the chilling cost of her new relationship being laid bare in this manner, Marie-Andrée succumbs and so, their arms entwined around one another, the pair fall against a wall and begin having sex. 

For her, it’s a passionate moment: she believes she’s the only person who’s seen beneath Sobhraj’s mask, and that theirs is a love unlike any other. For him, though, it’s proof that he’s managed to manipulate Marie-Andrée into doing his bidding – no matter what the cost.

As portrayed in the TV series, Marie-Andrée is shown not just helping to drug victims, but also using the stolen passports of Sobhraj’s female victims once he’s killed them to steal their money.

And it is worth noting that Marie-Andrée was charged with these same crimes in real life, despite protesting her innocence.

Speaking to Entertainment Daily about preparing for the role, Coleman says she read Marie-Andrée’s diaries to learn more about the woman she’d be portraying on screen – but that she still doesn’t know whether or not the Quebec native understood the truth about Sobhraj.

“Is Marie-Andrée a victim or not? How much of her was brainwashed by him?” the actor wonders aloud.

“How much was a choice to be there and a choice to live in the delusion?”

Coleman adds: “I think what’s really interesting is it’s almost like she created her own narrative.

“So I guess for me it was more about squashing the truth, it was kind of like not accepting the reality of what was actually going on and meanwhile she’s kind of almost like living her own movie star life in her mind, which made it really complicated in a great way, in a really great way.

“There kind of felt like in-between the lines that Richard [Warlow, The Serpent writer] wrote there were a thousand possibilities which kind of always draws you in.”

The third episode of The Serpent will air on Sunday 10 January at 9pm.

Images: BBC One