IF Brexit weren’t so life-changingly serious, it would be the greatest novel or TV drama ever written. It started two-and-a-half years ago with the simplest question in the smallest words - in or out – last night’s episode left us with an amazing cliffhanger.

Yes, there has been seem pretty turgid reading at times, but we’ve stuck with it and now we can feel that there are only a couple of pages left – the great denouement must come by March 29 - and yet we have no idea how the plot can possibly resolve itself. Every potential ending is deeply flawed and unworkable, and none of the characters appear strong enough to grasp the plot and write a happy ending.

Last night’s episode was jaw-dropping. The defeat of Theresa May’s deal was obvious, but no one seriously predicted that it would be of the largest magnitude in British history – 232 votes. Poor Mrs May has suffered some enormous personal humiliations in the last 30 months, but now her name goes down in the record books at the top of the list of biggest losses – she overtakes Ramsay MacDonald’s 1924 166-vote defeat by some way.

In the moment of that defeat, Mrs May pulled a clever little trick by calling a vote of confidence in herself, thus removing any satisfaction Labour might have gained from tabling such a motion. It would, though, be a stunning plot twist if she were to lose it today because as much as the Democratic Unionist Party hates Mrs May’s deal, it hates the thought of Jeremy Corbyn negotiating one even more. DUP votes will keep her in No 10.

But the magnitude of the defeat removes the most obvious plot development. If she’d lost by 100 or so votes, Mrs May would have attempted to refine her deal, rewrite a few passages here, gain a few concessions here, in the hope that bit by bit she’d get it passed. But that now seems impossible. Even if her refinements won over a few Labour switchers, it will not be enough and Brussels will look at the 230 vote chasm and say to her there are no concessions that the EU can give that will win that many people over.

So Mrs May announced her Plan B – that she would talk to a few people and see what happens. That in itself was another remarkable development. Mrs May’s period of office has been characterised by a failure to reach out beyond her close clique – three Brexit secretaries have resigned because she was doing all the negotiating. Realising she was in danger, she began reaching out to MPs a couple of weeks ago, offering a conciliatory tone but more than one North-East MP told her that it was too late, she had gone too far, and last night Mr Corbyn also appeared to rule out helping her.

And will she be able to listen to other voices, because it does seem that the only possible Parliamentary way forward is for a soft Brexit with Britain remaining in a customs union – yet that would cross one of her own red lines announced at the beginning of the process. She boxed herself in before she even began negotiating – but in giving her such a resounding hiding, the Brexiteers may have lost their best chance to Brexit. Her deal was flawed, but it did mean the UK left the EU – now, as the plot rollercoasters out of control, even that cannot be guaranteed.

Last night’s twist also shines the spotlight on another key character in the drama: Mr Corbyn. His policy has been to call for a General Election and today, if he succeeds or fails in forcing such a poll, he will have to develop his ideas.

If he wins and there is an election, Labour will have to take to the doorsteps telling voters if it is for or against Brexit – Mr Corbyn is probably for but many of his MPs, as in the North-East, are against. The Tory divisions, pulled between Jacob Rees Mogg on one side and Anna Soubry on the other, are bare for all to see – Labour’s equal divisions will be exposed in the campaign.

Similarly, if, as is most likely, Mrs May clings to power and there is no election, what will become the main plank of Labour’s stance? Will the party move on and throw its weight behind a hugely controversial second referendum?

So last night’s episode has left us with a real cliffhanger – yet the thinness of the Brexit book that remains unread tells us that within weeks we have to reach some form of conclusion: no-deal, no Brexit, soft Brexit, second vote. All endings are possible; all endings seem, from the page we are on at the moment, implausible.

Only a dramatic mastermind like Shakespeare could have written such a rolling plot crammed with sub-themes – the tragedy is that it’s real life, and the futures of our children and grandchildren will be profoundly affected by whatever unexpected twist comes next.