His behaviour looks all the worse next to Léa, who’s clearly seven going on twenty-seven. I liked her immensely from the moment she took my hand this morning and announced she was taking me to Montreux town centre to show me around, but could I drive? I said I would, and that we should take Luca too, and she reluctantly agreed in a manner that suggested she had a choice in the matter, but would do me a favour this time.

It’s chilly beneath the vaulted stone ceiling of Chillon Castle’s underground prison. I read from my guidebook and find the name Byron carved into a pillar, supposedly put there by the poet himself when he visited the castle two hundred years ago. Léa pretends to be interested, nodding solemnly as I read. Luca’s momentarily cowed into silence by the imposing room, until his sister whispers something to him and then he’s crying. I don’t need to speak French to know she’s threatening to leave him here. It’s clear we’re all castled out.

We walk back over the drawbridge and wander down the lakeshore a little way to sit on the wall and eat our picnic. Cheese and gherkin sandwiches, apples, and a fizzy drink called Rivella that Léa says is her favourite. The castle sticks out into the lake next to us. Whichever medieval bigwig built it certainly knew how to pick a spot: in front of us, the lake is flat calm, and the mountains on the other side meld shade upon shade like some perfect watercolour painting. I understand now why ladies in the nineteenth century came to Switzerland to cure their ailments. Not because of anything miraculous in the water – though it does look clean enough to drink – but because of this: the heady fragrance of the flowers decorating the promenade’s verges, the ducks bobbing on the tranquil lake, the solid bulk of the Alps a constant, comforting backdrop. It’s like I’ve stepped out of reality and into a picture book by a Swiss Enid Blyton. It’s summer, I have Michel’s credit card, Julia’s car and free reign to explore, my only task being to gently impart some of my own language onto two already semi-bilingual children.

It’s just what I need right now. My cure.

If only that’s all it was.