‘I’ve been given another assignment,’ Daphne says. ‘It could be dangerous. If this is the last time we see each other, please remember that I want to be buried with my vinyl copy of Johnny Mathis’s Warm.’

O’s lemonade glass is still half-full when it slips from her hand and shatters spectacularly on the tiles. I lunge towards her, afraid she’s going to actually faint, but she fixes me with those hawk eyes. Pinioned, I halt before I’ve touched her. Her expression is so empty that for a moment I wonder if she’s having a stroke.

‘I’ll get you another drink,’ I try to say, but my voice has deserted me. I scurry to the kitchen and nearly collide with our waiter. While he cleans up the mess, he flirts with O and Daphne both – not with me, I notice – sniff. Daphne is still under full sail on the topic of her ‘mission’.

‘Mathis was my favourite singer. I wonder if he’s still alive. Davies and I saw him having dinner in The Ivy once but I was too shy to ask for his autograph. I can remember that, you see. I can remember listening to his records as if it were yesterday. But now, what with me losing my mind, I’m worried about the assignment. I’ve been given a target, you see. What if I mix up the names and take out the wrong agent? Or what if I—’

O shakes her head sharply. ‘No, Daphne, we mustn’t talk about these things.’

Daphne lets out a quavering sigh. ‘It’s such a burden, sometimes. You wouldn’t understand. You lot have never had to— Oh, are those strawberries?’

‘Yes, have some, darling. Waiter! The cream?’

Deftly, O steers the conversation away from Daphne’s ‘assignment’ and somehow we navigate the rest of the meal. It’s a mix of alert chatter and utter confusion. I’m not sure if it’s just me getting used to Daphne’s illness, but I’d wager she’s improved slightly over the course of the last five or six visits. Sometimes she seems almost sharp, which makes her spells of confusion all the more poignant. Think Flowers for Algernon: the club remix.

Daphne normally insists on going for a long walk before we return to the residence.

‘They won’t let me out by myself, of course,’ she tells me, every time, ‘lest I should get lost, or mug someone, or run away and join the circus. But I was a mountain climber, you know. I’ve run triathlons. Astonishing that I should be afflicted with this brain disease, because I’m strong. I need exercise. One never knows what one may be called upon to do for one’s country. I like to be ready, just in case.’