May, Merkel and Europe's big problem
Two leaders, two women, two no nonsense, pragmatic, problem solvers are to meet at the start of a process of trying to solve one of the biggest they - and, indeed, Europe - has ever faced.
Theresa May knows that her host in Berlin today - Angela Merkel - will not be impressed by the soundbite, "Brexit means Brexit".
Why? Because the German chancellor, and the rest of the EU, are impatient to hear what Brexit really will mean for Britain's relations with those we once called our EU partners.
Those who have visions should go the doctor. That is what Angela Merkel told David Cameron in one of their first conversations about Europe when he tried to explain how Britain saw the future of the EU.
If there was ever a time for philosophising it is long since over.
'No flattery required'
The former British Ambassador in Berlin, Sir Paul Lever, says the German chancellor does not want to be wooed. She is waiting for answers.
"A charm offensive, in the traditional sense, with Merkel, is a waste of time," says Sir Paul.
"So if you want to get on with her it is best not to flatter but to be direct and clear.
"What Angela Merkel will want to hear is how does the British government now intend to play things, and in particular, when is it going to invoke the article of the treaty that triggers the process of the withdrawal."
But early impressions do matter with Merkel.
Cameron spent his first years in office having to repair the damage done when he announced that he was pulling the Tories out of their partnership with her Christian Democrats in the European Parliament.
It was - she believed - his first disastrous concession to the anti-EU forces in his party.
The prime minister is making it clear that she will not file for divorce from the EU before she and her government have decided not just what they want our relationship to look like in future - but what relationship is likely to be acceptable to those we're leaving behind.
Simple - say optimistic Leavers - let's trade pretty much as we do now because those Germans want to sell us their cars, don't they?
Matthias Wissman, a former German transport minister and now President of the German Association of the Automotive Industry, indeed does make it sound pretty simple.
"Britain exports 57 per cent of its exports of cars to the EU and the German vehicle makers produce more than 200,000 passenger cars in the Britain," he says.
"Furthermore, our suppliers have some 100 production sites in Britain. That means there are interests on both sides of the Channel which are very strong and which need for the future free access to the markets."
But the British and indeed the German economy is not driven by cars alone. Indeed the UK is much more dependent on selling things you can't see - services - than those you can.
Not least financial services. And when it comes to those the pressure on Mrs Merkel is to be much much less accommodating.
Artur Fischer, head of the Berlin Stock Exchange, is dismissive about British ministers saying they want full access to the single market while also wanting to strike their own trade deals and have less regulation.
"It is about having a cake and eating it! You can't have it both ways," Mr Fischer tells me.
"Either you have free access to the market and you play by the rules or if you don't want to play by the rules you can't have free access."
It is - David Cameron always used to say - Berlin or Bust.
That is because British prime ministers always get a much frostier reception in Paris - Theresa May's destination on Thursday.
But trade deals are not actually done by prime ministers or chancellors or presidents. They are not done in minutes or hours. They take months and years and highly trained, hard nosed, obsessive lawyers - lots and lots of them.
Before any of that can happen the negotiators on both sides need to know the answer to the question which will be posed by Angela Merkel and Francois Hollande - we know you want to leave us but what sort of relationship do you want in future.
Will it be like the Norwegian model, the Swiss model, the Canadian model?
With Theresa May in Berlin, Angela Merkel may revive her favourite English saying, "Where there's a will there's a way."
I heard her say it again and again after meetings with David Cameron. Even those at which she had refused to give him what he so craved - curbs to freedom of movement.
Britain, she used to tell him, was the EU's problem child. Now we're heading for the door, doing a deal with us is unlikely to have become any simpler.