Doctor Foster series 2: 8 HUGE questions and theories after episode 4's insane cliffhanger

It finally happened – horrid Simon (Bertie Carvel) got his comeuppance in tonight's Doctor Foster... but is there worse still to come?

What started off as an ironic reflection of the first series, with one-time mistress Kate (Jodie Comer) now paranoid that she'd been cheated on, has gradually escalated until Simon was left a broken man.

Will that be enough for Gemma (Suranne Jones) – or is she going to remove him from both of their lives, permanently? We've just about managed to compose ourselves after that spectacular cliffhanger to throw together a few thoughts on what might happen next.

1. Has Gemma killed Simon?

Gemma totally unravelled her ex-husband's life this week, having spent her time away formulating a complex revenge plot.

Simon's wealth, it transpires, is not all that it appears – Kate's parents bought their flashy new home, which is in her name, while Kate's godfather Mark actually runs the Courtyard Project. The sharp suits? Just for show.

Once Gemma makes clear to Kate the extent of Simon's obsession with her (more on that below), he loses everything: Kate announces plans to move to France and take their daughter Amelie with her. (She can do all this so speedily because her dad, Chris Parks, always had an exit strategy for his daughter in place, convinced that Simon would mess up eventually.)

Simon ends up with no home, no job, no money, no possessions and no family – but still refuses to admit defeat. Reiterating his earlier promise that he won't leave Parminster except 'in a coffin', Simon marches off, planning to grab son Tom (Tom Taylor), and that's when Gemma puts the pedal to the metal, bearing down on her unwitting ex-husband in her car.

Will she go through with it? Either way, there'll be consequences – from Gemma having murdered Simon, or from her having made the attempt. (We're predicting he'll survive, but that next week's finale will leave us hanging a little while before revealing his fate.)

2. What did Simon tell Tom to turn him against Gemma?

Just one episode left and we still don't know what it was that Simon revealed to his son to turn him against his mother so dramatically.

Tom, now reconciled with Gemma, is keen to move on ('It doesn't matter now, so can we leave it?') but Simon insists that the secret will have driven a permanent wedge between Gemma and her son. 'Tom will never trust you, not really. Not like he used to.'

What did Simon say?!

MORE: DOCTOR FOSTER ACTOR SAYS HIS ROLE PUTS HIM 'AT RISK'

3. Will Simon seek revenge?

When Gemma visits Simon in the episode's final scenes, he's at his lowest ebb, crying like a baby, and she's initially satisfied to silently mock him as he rages impotently, before driving away.

But then, Gemma has second thoughts. She returns and offers to let Simon stay for two nights in the same hotel room where she and Tom had been living. Not pity, she insists, she just wants to keep track of his movements before he leaves town forever.

It's clear Gemma's worried that Simon might attempt to strike back, and now he's got nothing to lose, he could be potentially more dangerous than ever. Presuming he survives, he now has even more ammunition and could get his ex-wife locked up for attempted murder.

4. Could Kate end up as Gemma's ally?

It's becoming increasingly clear that, while they're never going to be best pals, Gemma actually sees Kate as a kind of kindred spirit – she does what she does this week not to hurt Kate, but to free her from what she sees as Simon's poisonous influence.

'Tonight's a good night,' Gemma tells her old rival, after convincing her to leave Simon. 'You're not going to waste 15 years, and you're not going to bring up your child with a man who will damage her. Tonight's when you escape.'

Last we saw Kate, she was bundling Amelie into the back of a car, intent on leaving the country. But could she end up coming to Gemma's aid next week, if Simon does attempt one final ploy?

5. Could Gemma and Simon get back together?

We first suggested this last week – and yes, after the events of this latest episode, it appears deeply unlikely. But stick with us on this.

Simon denies he still has feelings for Gemma, insisting that their romp last week was purely physical. He even makes queasy overtures to Kate, insisting that he prefers her to his ex-wife. 'Your body's better... what you can do with it. You smell better!'

But as the episode unfolds, it becomes increasingly clear that Simon's totally and utterly obsessed with Gemma. He's stayed true to his original wedding speech (the item that Gemma gifted to Kate): 'She will be everything forever. My obsession. My life. There will never be anyone else and she will be my life until the day I die.'

There's even the skin-crawling revelation that Simon's started making Kate dress like Gemma. 'It's his taste,' Gemma says. 'His taste is me.'

He even played Gemma's favourite song, the song that she and Simon used to make love to, at his and Kate's wedding party – and Gemma, though she'd be loathe to admit it, is every bit as obsessed with him.

All the same, could they possibly get back together after all that's transpired between them? We'd argue not, except for one seemingly innocuous moment in this latest episode...

'What was your problem with James?' Gemma asks Tom. 'He wasn't right for you,' her son replied. 'You wouldn't have worked together.'

What was the point of this exchange, referencing Gemma's nice-but-dull love interest? Unless it was a hint that she and Simon are a good match, both equally unhinged and troubled? We're not ruling this one out just yet.

6. What will happen to Tom?

Gemma insists that she and her son can return to Parminster once Simon's defeated. Tom's apologised to Isobel, the school friend he assaulted, and Gemma has appealed his exclusion from school.

But even if the Simon situation somehow gets resolved, will Tom's reintegration really be that simple? He's clearly deeply troubled – this week, Gemma finds him sat in a bathtub, weeping, and she has to wash him.

Surely it's not going to be as simple as Happily Ever After?

7. Are we getting a third series?

Suranne Jones has indicated that another series of Doctor Foster could happen if the story's right, but series creator / writer Mike Barlett has hinted that 'depending on what happens at the end of series two, a third might not be possible.'

Surely, with Gemma pushed to attempted murder, there's only so far Bartlett can take her story without stretching credibility? What next, Gemma behind bars? Throwing disastrous dinner parties in the prison canteen?

We're anticipating a very final end to the Doctor Foster saga next week.

8. How much do we all love Chris Parks right now?

Kate's dad Chris (Neil Stuke) was every single audience member this week, positively beaming as Simon got his just desserts. 'Here it is, f**king snapping!'

Phenomenal stuff.

Doctor Foster continues next Tuesday at 9pm on BBC One.

Images: BBC. From: Digital Spy