Will she stay or will she go? Join the great Dr Foster TV debate

THE table is set for the most excruciating, embarrassing – and explosive – dinner party of the year. And eight million viewers are expected to join them for the final episode of Doctor Foster, the smash-hit BBC1 drama about marital infidelity.

All are desperate to discover how Dr Gemma Foster, played by Suranne Jones, extracts her revenge on her adulterous husband Simon.

She has cunningly engineered the tense dinner party with Simon, his mistress Kate Parks, Kate’s brother Andrew, and Kate’s parents Chris and Susie, who know nothing about the liaison.

They are all blissfully unaware about what is to going happen but begin to suspect trouble when an increasingly irate Gemma tells them: ‘I’m a wolf tonight.’

The Mail on Sunday is not revealing any of the plot lines from the final episode – to be screened on Wednesday at 9pm – but we can confirm that the dinner party is just one of a number of explosive scenes in the show’s heart-stopping finale.

Over the past four weeks fans have been on tenterhooks while Foster goes to increasingly desperate lengths to first prove her husband’s affair and then to plot her revenge.

Mike Bartlett, the show’s writer, said: ‘My own mum said to me, “Promise me that the show is going to have a proper ending.”

‘I don’t like these shows which have endings that are all sort of vague so I can promise everyone it has a proper ending.’

He added: ‘It’s all going to come out. It’s full-on and there is no messing around.’

Mr Bartlett believes that audiences have developed a soft spot for Gemma, saying: ‘They don’t necessarily approve of everything she has done but they have an attitude towards it – “Well, she should have done that and she shouldn’t have done that…”

‘If your friend was going through this, you wouldn’t approve of everything they did and you wouldn’t necessarily like everything they did but you would care about them and you would want things to be OK. Speaking to people, they seem to have that reaction to Gemma.’

Here, The Mail on Sunday provides its own guide to the key characters in TV’s most torrid affair – and what they might do…