The second series finale of Doctor Foster may have been somewhat overshadowed by that mistake (you know, the one everyone’s been chirping about on Twitter), but it still managed to catch us off guard.

So, naturally, when we learned that there was an alternate ending to the BBC One drama, we were all ears.

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

During the episode (3 October), we watched as Gemma (Suranne Jones) prevented her ex-husband, Simon (Bertie Carvel), from committing suicide. While she would never be willing to “forgive” his affair, she told him, she would be willing to “forget” it for the sake of their son, Tom.

Unfortunately, though, Tom (Tom Taylor) had other ideas. Gemma soon discovered that her teenager, sick of his dramatically feuding parents and their vindictive games, had run away from home in order to estrange himself from them entirely. 

The show ended with the titular character breaking the fourth wall as she addressed her son directly, pleading with him to come home whenever he was ready to do so (a directorial move questioned by some fans on social media).

Now, though, show writer Mike Bartlett has revealed that the show’s original ending was very different – and far more hopeful than the one which made its way onto our screens.

Speaking to Radio Times, Bartlett admitted that Tom never disappeared in the original draft. Instead, he remained at his mother’s side and helped her to forge a newer, more peaceful life in Parminster.

“The ending of the show unfolded as I was writing it,” he said. “In the plan he's in the car at the end. They go back to her house and get a new kitchen and try to build a life.”

Explaining his decision to change the plot, Bartlett added: “Tom's not a little child any more, he's going to make his own choices. And so hopefully it's one of those ones which you don't see coming but when it happens you look over the whole series and realise this has been coming the whole time.

“I was so involved in Gemma and Simon's story that's all I was thinking about when writing it.”

Read more: Doctor Foster slammed by health experts over these “dangerous” scenes

Whatever people thought of the finale, Doctor Foster has certainly made its mark on TV. Ever since the first episode aired, fans of the BBC One show have enjoyed bandying about complex theories, discussing earth-shattering spoilers, sharing commentary on the original (it’s based on a play) and praising the drama’s approach to sexual assault and consent.

And, although the BBC is yet to confirm whether the gritty drama will be back for a third series, Bartlett has hinted that there is room for more chapters to the modern tragedy.

He added: “I think it works as an end to this series and all the things that have been going on. Clearly there's potential there. But obviously there would have to be lots of conversations.

“We need to talk – Suranne and I and lots of other people need to have lots of conversations.”

Images: BBC One