Caro read from the leaflet as we walked round. She didn’t need her chair the whole time and she’d get out when she felt like it to stretch her legs. Except when there was an ice cream kiosk in sight and then she was straight back in it so we could jump the queue.

‘There’s an orchid house too. Cacti and succulents, we’ve done them. Greenhouses, done. Ponds. Palms. Ooh a physic garden! This way, come on.’

We came to a small area near the back wall marked ‘Plantes Medicinales’. Raised beds packed with shrubs. Caro knew what they all were from studying the little signs. I knew nothing because it was all in Spanish.

‘So what have we got here?’ she said, bending over. She plucked a sprig of lavender and held it against her face, inhaling it deeply. ‘Mmm, no better smell.’ She handed it to me. I smelled it too. If I hadn’t felt so sick and headachey from all the alcohol I’d consumed that morning, I’d have agreed.

‘Spearmint, Echinacea, yarrow, sage. Evening primrose. Oh, I adore primroses. They’re my favourites. We used to go picking them as children. You’re not allowed to these days.’

‘I used to take that for my bitch fits. PMS.’

‘Evening primrose? Did it work?’

‘No, not exactly.’

‘Arnica. Peppermint, lemon balm, marigold, rosemary, St John’s Wort. That’s mmm, that’s witch hazel.’

‘Can you bathe your vadge in these?’

‘What?’

‘Nothing.’

Caro rolled herself towards the next section – ‘Plantas Peligrosas. Have a guess what that means.’

‘Plants they use to make Pellegrino?’

‘Dangerous Plants,’ she said with a twinkle. ‘Henbane, Manzanilla – apple of death. Strychnine, Brugmansia – Devil’s Breath – Belladonna and Hemlock too. That’s how Socrates died, hemlock.’

‘Oh right.’

She fumbled around in her handbag and produced a pair of small white gloves, pulling them on before bending over and tearing up a couple of sprigs of hemlock, wrapping them carefully inside a clean hanky.

‘What are you doing?’

‘Picking some. If it gets too much I can boil this up in water and knock it back, can’t I?’

I wandered on behind her as she took sly cuttings of all the most poisonous plants in the garden, all of them bearing yellow ‘No tocar!’ warning signs and each one with several more exclamation marks than the last.

‘You won’t be allowed to take them back on the ship,’ I told her. ‘How are you going to get them through security?’

‘I’m an old, disabled woman. Officials tend to rush me through because I hold everybody up. Carry on, I say. Use their own prejudices against them.’

I got that. And I’ll admit it was useful having Caro in a wheelchair. People gave us the best tables, pushed us to the front and generally ignored us wherever we went. But I still didn’t like her taking the plants.