Paul decides Ruby’s cakes are ‘a little bit of a mess’ and Prue adds they have the ‘texture of a slightly under-baked polenta cake’. Paul tries to be positive by saying the ‘flavour’s fantastic’ but Prue concludes they’re ‘not your best’.

Prue loves the coffee bean flavour of Briony’s espresso madeleines but her mojito ones aren’t such a hit. Paul says he isn’t getting the lime (or the mint) and Prue says ‘I like your rather zany icing… but we were looking for perfection’.

Rahul achieves a ‘perfect hump’ and Paul judges them to be ‘absolutely delicious’. Prue adds they’re ‘a real little triumph’. Outside, Rahul asks one of the production team ‘can I ask you something – why people are laughing about ‘hump’?’

At three and a half hours, we’re told the bakers are about to embark on the longest Technical Challenge ever. Prue’s torta setteveli (or seven veils cake) consists of two layers of chocolate genoise, two of hazelnut bavarois, a crunchy praline base and a layer of chocolate mousse that’s coated in a mirror glaze. She advises ‘you’ve all got a freezer – use it’. As she and Paul tuck into the exemplary torta, Prue admits they’re ‘asking the near impossible’.

Despairing that she’s never made a chocolate mousse, Kim-Joy says ‘I don’t know what I’m doing’ and the exhaustion of nine weeks of intense baking leaves her sobbing ‘I think I’m just ready to go home’. She pulls herself together in time to hastily whip up a second batch of mousse, then skims the surface of her cake before quickly dousing it with mirror glaze. Convinced she has nothing to lose but the challenge itself, Kim-Joy expects to take the bottom spot. However it’s the ‘rubbery’ consistency of Rahul and Briony’s mirror glaze that fails to tickle the judges’ fancies. Prue says it’s like a ‘PVC overcoat’ and Paul likens it to ‘a pair of incontinence pants’. Best not to dwell too long on Paul’s knowledge of latex underwear. No really – stop thinking about it!

So Kim-Joy hoists herself into second place and Ruby tops the setteveli quartet. Coming fourth in the technical, Rahul says ‘as soon as something good happens, something bad just comes behind it’.

On to the Showstopper and we’re treated to another of those superlative statements – ‘the most complex patisserie challenge in Bake Off history’. It certainly sounds complex, as the bakers must produce ‘a Parisian window’ of three-dozen delicacies – puff pastry mille-feuille, a choux concoction and pâté sucrée tartlets. At this point we’re not told if the windows will be edible or just a clever display feature.

Ruby is working next to a little bunch of freesias as inspiration for her florist’s window of pastries. Lemon verbena tartlets are topped with Swiss meringue peaks and edible flowers; mille-feuilles are stacked with strawberries and mint and there are chocolate and hazelnut St Honores on a shortbread base.

Sandi describes Rahul as ‘playing it safe’, which doesn’t bode well for his prospects. He’s using the same crème pat in all three – a lemon and blueberry mille-feuille, caramel eclairs and ‘classic’ glazed fruit tarts. Briony’s motto is ‘go big or go home’ – she’s taking the risk of perfecting a proper puff pastry, whilst the other three bakers are rolling out a quicker rough puff. Briony is packing her puff with coffee and walnuts, whilst crafting chocolate domes to sit atop her Black Forest-inspired tartlets. Vibrant raspberry and lemon eclairs complete her trio.

There’s perhaps a little disappointment for those expecting a shop window of patisserie pets from Kim-Joy, though she is planning some feathered icing for her lemon and blueberry mille-feuilles. Her mango and passion fruit tarts are topped with crisp French meringue and she’s making twelve choux religieuses (the infamous nun buns) filled with orange crème diplomat and a craquelin crust.

On to the judging and… there’s not a pane of glass in sight. Apparently the ‘Parisian window’ was imaginary – something for the bakers to strive towards – a mirage that might appear, like Shangri La or Brigadoon if any baker achieved the required level of perfection. Paul examines Rahul’s tartlets and tells him ‘you can’t put this in a shop window – it’s not finished’. It’s all somewhat surreal.

Prue can taste salt in Rahul’s choux but she thinks the overall flavour is ‘lovely’. Paul disagrees: ‘I don’t like the flavour – it’s boring’. Prue tucks in to his seemingly underwhelming mille-feuille and decides ‘I didn’t think I was going to like that at all – it’s delicious!’ Paul agrees it has ‘great flavour’ and the anxious baker looks momentarily less anxious... and then that fleeting moment is gone.

Briony’s eclairs are even saltier and she senses she may have made that old Bake Off error of mistaking salt for sugar. Her time-consuming puff pastry is too raw for consumption and her tarts are ‘too thick’. Briony looks well and truly fed up as Prue tells her ‘you can do much better than this’ and ‘this was not the time to get it wrong’.

Kim-Joy apologises for the lack of feathered icing on her mille-feuilles and Prue says they look ‘very dull’. Paul says her bakes are ‘quite chunky’ though the flavour is ‘wonderful’. Prue admires the well-filled choux buns though Paul threatens to pick a fight with the topping, saying ‘I don’t agree with that craquelin’.

Ruby’s lemon verbena tartlets are ‘too strong’ and Paul petulantly pronounces ‘I don’t like unglazed fruit’. (I may be becoming as picky as he is – the sight of an even number of berries makes me wince.) Despite being ‘too big’ the overall look is ‘very pretty’ and her puff is perfect.

To be fair, everyone has had a pretty mixed week so it’s tricky to identify a Star Baker. In the end, Ruby’s ‘polenta’ madeleines and naked fruit tarts are trumped by her top Technical and comparatively delicious flavours. Poor Briony has endured nine weeks of bravely nodding ‘okay’ through criticism that’s not always been constructive. She’s right to be proud of her achievements and she leaves with an undaunted smile.

Meanwhile, there’s a character hanging around who is less than happy… the Parisian window cleaner is still waiting to be paid.