It felt as if the universe was on their side for once, at least: there was an easy parking space on arrival at Gyllyngvase, the clouds obligingly melted away from the sky as they stepped onto the sand, and there was a busy, happy atmosphere with people enjoying themselves, but not so many crowds that they couldn’t find a good spot to lay down their towels and beach mats. Perfect choice, Em, she congratulated herself. Maybe, just maybe, this could end up being one of those rare days when everything just clicked smoothly into place, as if all part of some very carefully and expertly engineered design.

George suggested a game of Frisbee and Izzie and Jack were both enthusiastic, while Em seized the chance for some bonding with Seren by helping her make sandcastles. Kneeling beside the little girl on the warm sand, the sun casting freckles on her shoulder-blades, Em felt a new optimism wash through her. This was going well, she told herself proudly, scooping sand into a red bucket. Everyone was having a nice time. She and George were bonding with each other’s children. They would look back on this day as the turning point of the holiday, after which—

‘My mummy is prettier than you.’

Ouch. Was Em’s deep-seated paranoia making her hear voices now? ‘Sorry, what, darling?’ she asked, taken aback. She turned the full bucket upside down and plopped it onto the sand. ‘Do you want to bang the top with your spade to make sure the sand doesn’t stick?’ she asked pleasantly. Surely she’d misheard. Of course she had!

‘My mummy is really pretty. And kind. She makes very good sandcastles,’ Seren said, her face unnervingly blank as ever. ‘And,’ she went on, with a glance at Em’s pale dimpled thighs, ‘she’s not fat.’

‘Oh,’ said Em. Double-ouch. ‘Well, that’s nice,’ she managed to say evenly. Do not rise to it. ‘Good for Mummy. But we’re going to make some great sandcastles ourselves now, aren’t we? We’re going to make an absolute palace!’ She gave her best and kindest smile as she patted the bottom of the bucket and then slowly lifted it, to reveal the moulded sand shape beneath. ‘Ooh, that’s come out well,’ she said, feeling rather pleased with herself. Let it not be said that Em Hughes was an amateur sandcastle-maker, she thought with a flash of triumph. She’d certainly had a few more years practice than . . . ‘What are you doing?’ she yelped in alarm as Seren, without warning, picked up a yellow plastic spade and smashed in Em’s sandcastle, with all the ruthless abandon of a psychopath.

‘I want to do the castles,’ Seren said, chopping the blade of her spade through the sandy wreckage.