EVERY fan of horror movies knows the moment of maximum danger is when the terror seems to be over.

Picture it. The survivors sitting around giddy with relief. Maybe someone tries a lame joke that the others laugh at a little too hard. Who can blame them? What a dreadful time it has been, but hey, this too has passed.

Then it happens. The detective opens the box, the kid in the red coat turns around, and have you met mother in the basement? The horror, the horror, best served when your audience least expects it.

Which brings us to young Mr Rishi Sunak, as seen on Tuesday going through the door at Number 10 and disappearing into a crowd of smiling onlookers. At least I think they were smiling...

You could almost smell the relief at Prime Minister’s Questions yesterday, and not just on the government benches. Having lost Liz Truss, it was touch and go there for the Opposition parties. It seemed the Conservatives had finally done the right thing, after all other possibilities had been exhausted, and chosen the smartest guy in the room to be their leader.

So what if they had initially rejected him, he was here now, and the Conservatives were going to live happily ever after, or at least until 2024, right?

The first sign that something was amiss came shortly after Mr Sunak’s victory was announced. The first people he spoke to, behind closed doors, were his backbenchers. Then it was on to Conservative HQ for a brief, quasi-public statement after which he took no questions. Weirdly, he ended his speech that was not a speech by looking round the room then walking off, a tactic known as “doing a Liz”.

That was all he had to say to a waiting public that had been put through the wringer so many times lately and feared more of the same was on the way.

I heard one Conservative Minister defending Mr Sunak’s silence as only to be expected. He had not, after all, officially become Prime Minister. That could only happen once Ms Truss had resigned and the king had asked Mr Sunak to form a government. All true, in theory, but in reality it was a pretty poor show. Instinct should have told him that the public was the priority here, and propriety could take a back seat.

More strangeness followed when he arrived in Downing Street. It was not the speech itself, a curious mixture of score-settling and what Sarah Palin called “all that hopey changey stuff”. It was what happened later after he had promised to put “integrity, professionalism and accountability” at the heart of his government. Of all the possible candidates to be the Home Secretary he chose Suella Braverman, the person who, only a week ago, had to resign for breaking the Ministerial Code.

She lost her job because she had emailed a confidential document from her personal email account to a backbench colleague. Up to that point she had hardly covered herself in glory. Indeed, her appointment in the first place was seen as a prime example of Liz Truss’s spectacularly poor judgment. But even she recognised Ms Braverman had to go. What does it say about Mr Sunak that he did not see anything wrong with the reappointment, and was prepared to defend it to the hilt at his first Prime Minister’s Questions?

Was he pushed into such a toxic position because he needed to buy the support of the right in his divided party, or did he jump of his own free will? Either way, it stinks.

The defence put forward by Ministers is that Ms Braverman made a mistake, she apologised for it, stood down, and she can therefore return to the Cabinet. If that is how low the bar is being set, Mr Sunak is in for an even livelier time than his predecessor endured. As for bringing back so many old faces from the only too recent past he either does not see the problem or does not care. Either way it hardly inspired confidence that this was a Prime Minister who “got it”, who understood.

Not that you would have seen any problems ahead at Prime Minister’s Questions. The Conservative benches were full of men and women of good cheer. A party in the mood to par-tay, and Mr Sunak was ready to indulge them. It was another misjudgment.

This was not the sombre Mr Sunak who walked up Downing Street on Tuesday. This looked like a Prime Minister having a jolly time fulfilling a long held dream. Give him a box file in place of a despatch box and he could have been a lad pretending to be Prime Minister.

PMQs were a pointer to how the rest of Mr Sunak’s premiership might play out, with Opposition MPs losing no time in raising the subject of his wealth. When spending cuts are announced and times get even tougher he will be in a difficult position. The same goes for his wealthy Chancellor. It was bad enough being told by George Osborne, the original austerity Chancellor, that we were all in this together. Imagine hearing that message from Messrs Sunak and Hunt.

Mr Sunak in particular is not wealthy in the way other Prime Ministers have had a few bob to their name. He is rich beyond most people’s comprehension, and like other very rich people his financial arrangements will be complicated. Does he really wish to explain them to any MP or Opposition party who asks, as they surely will?

The last time his family’s tax arrangements were questioned he reacted by withdrawing from the spotlight. Friends made it known that he was deeply unhappy at his family being dragged, as they saw it, into public life.

That was when he was Chancellor; now he is Prime Minister the scrutiny and pressure can only increase.

It is worth noting that Mr Sunak entered Downing Street on his own on Tuesday. There was no photo of him on the doorstep with his wife and children. That might have been his way of signalling that he stands alone as Prime Minister and everything else is out of bounds. One can understand why he should feel that way. How realistic it turns out to be is another matter.

Does he appreciate the scale of the task he has taken on, and how angry and despairing people have become under his party’s watch? Check the time, Mr Sunak, there is a long way to go till the credits roll on this tale.

Read more by Alison Rowat:

Sketch: One out, one in, it’s all change on Coronation Street

Sorry, I agree with the BBC's Nick Robinson on this one