Doctor Foster's sizzling series 2 opener is appointment TV

Gemma is the top doctor in a thriving clinic, has developed a good relationship with the teenage son who was formerly critical of her parenting style, and still loves a decent cup of coffee. Extra strong.

In fact, the only thing that could possibly threaten her happiness is an unrepentantly perky and seemingly hyper-organised new colleague, Sian (the excellent Sian Brooke), who oozes enough passive aggressive energy to power the National Grid.

That is until a red envelope arrives Chez Foster, addressed to teenager Tom (Tom Taylor), and reveals that snakey Simon, Kate and their baby are finally coming home – and throwing a big wedding celebration for all their friends in their ridiculously fancy new house.

I defy any devotee of the series not to mumble “the bastard” as realisation dawns. Gemma Foster, I’m guessing, would have a few more choice terms for her ex-husband, who became something of a national villain when he consistently lied about his two-year affair with a colleague's daughter back in 2015.

The five episode series had viewers hooked and when it ended in dramatic fashion - and Simon's departure for London with his pregnant mistress - audiences felt some sense of justice for a GP scorned.

Simon's return to Parminster threatens not only the stability of the happy world Gemma’s worked so hard to build with her son, but her own mental stability too. Just one encounter with Simon is enough to bring the pain of his betrayal flooding back, and awaken Suranne Jones’s superb tigress who came to tea (and went home with a well-deserved Bafta).

Grief was part of the driving force behind her dinner party massacre in series one, but Gemma’s channeling pure anger this time around. Jones masterfully allows her frustration to trickle out in the odd pained glance, twitching eyebrow or scratching finger, before blind fury erupts in the form of erratic and impulsive decision making.

Many of Gemma’s impulsive decisions result in deeply uncomfortable one-on-one encounters with Simon, who has supposedly returned to town to put the past behind him. There’s something about his new calm and self-confident exterior that’s brilliantly disquieting and utterly infuriating to boot. Bertie Carvel beware – there may be shouting in the streets.

Mike Bartlett's consistently compelling writing is at its finest when the two are left alone to verbally spar. He's got a knack for tapping into Jones and Carvel's cracking chemistry and bringing out the best – or narratively worst – in his leads.

“You’ve got two characters there, where the hurt has really set in,” explains Jones, who says the divorced couple we meet at the start of series two are “vulnerable, damaged people”. It’s a tough sell for an audience that struggles to find sympathy for Carvel’s adulterous on-screen alter ego. Gemma Foster isn’t the only one who thinks it’s “good to know” the only way he’s leaving Parminster is “in a coffin”.

Even Carvel, who generally refuses to judge the characters he plays says “it’s hard to watch an episode like this and not admit to being the bad guy.” Take it from us, you may well have to resist the urge to shove Simon into said coffin and send him to an early grave yourself.

That’s the brilliance of Mike Barlett’s Doctor Foster though. It’s a series so compelling you can’t help but be sucked in and those who feared a second outing might somehow ruin the magic of the first can rest easy. Series two gets off to a thrilling, infuriating and deliciously dark start, with a stunning cliffhanger ending setting the stage for Jones to work the kind of magic that only she can.

“What betrayal does to a person can make them ugly”, she teases. It’s enough to leave the audience begging for a repeat prescription.

Doctor Foster series 2 begins on BBC1 on Tuesday 5th September at 9pm