Please be aware that this article contains spoilers for the second series of Doctor Foster, so don’t read on unless you’re up to date with the BBC show.

Doctor Foster, at a first glance, feels like an incredibly modern tale, focusing on the disintegration of the ‘perfect’ marriage and nuclear family – not to mention the destructive powers of infidelity, lust and revenge.

So it may come as a surprise to learn that the BBC drama is actually based on a story that’s almost 2,500 years old.

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Mike Bartlett, the writer of the hit BBC One show, has confirmed that Gemma Foster (Suranne Jones), was originally conceived as a contemporary version of the titular character in Medea, a Greek tragedy about a wife who seeks violent revenge for her husband’s infidelity.

“In the original pitch, I never actually said, ‘We’re going to do Medea at 9pm on BBC1’ because it probably wouldn’t have gone down very well,” he told the Radio Times. “But that idea was always behind it.

“I wanted to take some of those misogynist ideas about mad women and witches, and hopefully subvert them.”

However, as students of Euripedes will know all too well, Medea absolutely does not have a happy ending (hence the term ‘Greek tragedy’). And, if Doctor Foster is going to continue to mirror the plot of the 431BC play, it will end with the murder of a very surprising character…

In one version of the story, Medea murders her own child in a last ditch attempt to break the heart of her unfaithful husband, Jason – which means that Gemma could be set to kill her beloved son, Tom (Tom Taylor).

However, there is another version of the dark tale, which sees Medea and her son work together to murder Jason and his new lover, Glauce.

Could Gemma and Tom – having seemingly fled Parminster at the end of the last episode – be preparing the ultimate revenge on Simon (Bertie Carvel) and his young wife Kate (Jodie Comer)?

Read more: The tiny detail in Doctor Foster that hints at a major plot twist

Perhaps realising that he’d let a spoiler or two slip, Bartlett refused to comment on the upcoming series finale. However, he did allow that a “third (series) might not be possible”.

“Depending on what happens at the end of series two, a third might not be possible. That’s all I can say really.”

Despite Gemma’s increasingly erratic behaviour, Bartlett also felt compelled to defend his (potentially murderous) titular character from slurs and criticisms online.

“I get upset when people describe Gemma as mad,” he said. “I don't think she is, she's just very angry.

“If it was a man behaving like that, you wouldn't say he was mad. You'd say he was fighting back.”

Doctor Foster airs Tuesdays at 9pm on BBC One. 

Images: BBC One