It is all too easy, when watching BBC One and Netflix’s The Serpent, to forget that its based on the true story of Charles Sobhraj (Tahar Rahim) – aka the same serial killer and conman who brutally murdered and robbed at least 12 Western tourists along the so-called ‘hippie trail’ in the 1970s.

“The Serpent keeps giving me the chills knowing it’s based on true event,” tweeted one fan of the TV show.

“Is it OK to be loving The Serpent since it’s based on real events?” asked another. “Asking for a friend.”

And still one more has tweeted: “If The Serpent wasn’t a real story I would dismiss it as too far fetched. But it isn’t fiction: it is real, gripping, horrifying and so worth watching.”

In the show’s fifth episode, we leap back in time to find out what really happened to Nadine (Mathilde Warnier) – albeit this time through the eyes of Sobhraj himself. 

He forces her to down drugged cocktails, to punch him in the stomach, to be punched in the stomach herself. He watches her swim seemingly endless laps of the pool. And, all the while, he teeters on the brink of disaster as our oh-so-square hero Herman Knippenberg (Billy Howle) works with the police to finally, finally make their move.

Cue a much-anticipated raid on Kanit House, as the serial killer – along with his loyal accomplices, Monique/Marie-Andrée Leclerc (Jenna Coleman) and Ajay Chowdhury (Amesh Edireweera) – is taken in for questioning.

If you thought this would be the end of it all, though, you’d be sorely mistaken (it did take the real-life Knippenberg some 30 years to get Sobhraj behind bars, after all).

So, how did Sobhraj manage to escape this time? Through a complicated concoction of wiles, deception, and gentle manipulation of a corrupt police department, of course.

How did Charles Sobhraj escape prison?

Before the raid ever takes place, Sobhraj pays a visit to his girlfriend, Suda (Chicha Amatayakul) , a jeweller whose dad just so happens to be a top-ranking police officer. Handy, right?

Much as we’ve seen him do to Marie-Andrée throughout the series, Sobhraj launches a full-blown charm offensive on the young woman, ’love bombing’ her with a fat engagement ring and promises of a new life in Paris. The only catch? He needs her to hold onto a very suspicious red suitcase for him and keep it out of sight from anyone, absolutely anyone, who might be looking for it. 

This is the same very suspicious red suitcase he’s filled to the brim with stolen passports, we hasten to add. As in, yes, the same stolen passports that could and would provide police with more than enough evidence to keep Sobhraj in chains for a very long time.

How did Charles Sobhraj manage to charm so many people?

While it’s unclear whether or not Suda is based on a real person, it is worth noting that Sobhraj was a narcissist who famously prided himself on his ability to read and manipulate people – particularly women. 

As per GQ’s Andrew Anthony, who interviewed the real life serial killer, Sobhraj “analysed character according to a system devised by the French psychologist Rene Le Senne, a method he used to impose himself on the gullible. 

“He was also a student of the philosopher Friedrich Nietzsche’s “will to power”. In 1975, when the Nepal police raided Sobhraj’s hastily abandoned hotel room after Bronzich’s body was discovered, among the few items they found was a copy of Nietzsche’s Beyond Good And Evil.”

“If you use it to make people do wrong it’s an abuse,” Sobhraj explained to Anthony, when asked about his penchant for coercing people into doing his bidding. 

“However, if you use that power to make people do right, it’s OK.”

Back to the TV show, though, and Sobhraj has a plan: first, he asks Marie-Andrée to put on all of her jewellery (which he uses to bribe a crooked cop). Then, he doctors one of his victim’s passports, and uses it to support his claim that he’s an American citizen called David Allen Gore, before undergoing the weakest interrogation of all time ever.

Despite all of this, though, Knippenberg and his wife Angela (Ellie Bamber) are convinced they’ve made good on their promise to get Sobhraj behind bars, especially when they learn that the real David Gore was a victim of a robbing in Hong Kong. So they pour themselves a glass of something sparkly to celebrate, sit down, and breathe a sigh of relied.

And then, of course, the telephone rings.

“They’ve gone. They left the doors open and they walked out,” a police detective awkwardly informs Knippenberg (we guess that bribe worked). 

No wonder he’s left screaming over Thailand’s corrupt and inept justice system, eh?

How did Tahar Rahim get into character as Charles Sobhraj?

Sobhraj pays a visit to Suda, has dinner with his new fiancée, then leaves with his shady, shady suitcase and that engagement ring, which he promptly bestows upon Marie-Andrée. How romantic.

“Here comes the future,” he says. And, while we know what that future holds eventually (prison, damn it!), we also know that the IRL Sobhraj continually managed to evade justice by doling out bribes left, right, and centre.

Speaking about his slippery character, Rahim says: “It’s a very complicated character to portray, it’s easier to get out of a character, sometimes than to get in.

“I remember I struggled the two first weeks, it was hard for me to, to capture him to understand him. Because, how can you possibly be real, and in a way, truthful, when you have to portray those type of people?”

He added, as per The Express, that he found it easiest to pick an animal to base his performance upon – one closely connected to the show’s title.

 “The cobra is very still, and when he bites… then there’s kind of a charm around this cobra thing.

“At some point, I just let my imagination and my guts lead me to something that I feel is kind of truth.”

The Serpent continues on Sunday 31 January at 9pm on BBC One, with all episodes available to watch on BBC iPlayer.

Images: BBC One