The music starts automatically, the ice-cream jingle, ‘Que Sera Sera’ on imitation chimes. Gulls scatter as the truck eases forwards, trundling towards higher ground. The tourists, for the most part, tend to keep to the safety of the dunes, bracketed behind canvas windbreakers, hunkered grimly over sandwiches and picking sand from the spines of overambitious holiday books. Every year, the coastguard finds on average six copies of Anna Karenina abandoned on the flats between April and high summer. The council has plans for a small exhibition.

Wondering whether she ought to stop and scoop up the wrapper, Alice glances at Min, only to find her bunching up her chewing gum in a paper napkin, preparing to throw it out of the window.

‘Oh, don’t,’ Alice says, regretting it almost immediately – the mumsy tone. Min raises an eyebrow at her, though she does withdraw her hand from the open window, throwing the napkin instead in the cupholder beside the gearstick.

‘Fair enough,’ she nods, and while her tone is light Alice feels she can detect the faintest note of mockery. ‘Mustn’t be bitter with my litter.’

It can be like this, sometimes. A sudden quirk of the lip. Alice biting back the wrong words. Sitting together in History, passing notes until Alice writes something stupid or uncool, underlines the wrong thing, and Min crumples the note in her fist.

‘Fair enough’, this stock phrase, its cringing detachment. The sudden removal of camaraderie and Alice clawing after it.

‘Earl Grey and sardine ice cream it is,’ Min replies, and Alice grins despite herself. It is a sleepover game they play, dreaming up the most disgusting of possible flavour combinations: lemon curd and spare ribs, duck and Parma Violets, tinned pilchards and strawberry jam. A strange pretence at early teenhood, despite the fact that they are both nearly eighteen – nights spent sleeping top to tail in Alice’s bedroom and playing stupid games, inking outlines of the constellations on one another’s arms in biro, tweezing eyebrows and talking on and on about kissing, Min’s little moonstone teeth in the dark.

At the serving hatch, Min hooks one bony ankle over the other and Alice wills her to retract her head and wink at her, give some sign that they still share ownership of the joke she has just hurled unthinkingly away from them. But Min remains where she is and the joke sails away over the head of the boy whose fingers now appear on the edge of the hatch.