With another groan, Ceci threw up violently.

‘All right, lovie. There you go. Better out than in, eh?’ Wellies had been the best bet after all. ‘Zach, sit her down somewhere while I get Mel.’

Hurriedly, I beckoned my friend over the closing strains of ‘Fix You’ – a song I’d happily never hear again.

‘What’s up?’ Melissa joined me, leaving the others still singing, Nella swaying with eyes closed, Rebekah with her Tupperware boxes at her feet, filming everything on her phone religiously.

‘Ceci’s not well, Mel. She went in the pool.’

‘What pool? Oh, the lake thing.’ It was properly dark now as we hurried back. ‘God, why?’

‘For a dip apparently – and now she’s being really sick.’

‘Oh, bloody hell.’ Melissa’s torch flicked through the trees as we both stumbled over a fallen branch. ‘Ouch.’

‘Ceci?’

The girl was crouched, shaking, Willow holding her hair for her.

‘I don’t feel very good,’ Ceci moaned.

‘It’s OK, sweetie.’ Melissa bent to hug her stepdaughter. ‘I’m here now. Thanks, Willow.’

‘No worries.’ The girl stepped back. ‘Poor Ceci.’

‘Might have been one of those chicken legs,’ I muttered to Melissa. ‘Or a sausage?’

‘Seems a bit quick though, doesn’t it?’ Melissa hauled the girl to her feet. ‘More likely a sneaky cup of wine or two. Come on, honey, let’s get you back to the tent. You’ll feel better once you lie down.’

Zach was slumped on the ground now, head in his hands.

‘Bad tummy?’ I stroked his hair, not wanting to believe what Melissa had suggested. But although Zach didn’t feel hot, he did look strange, now I could see him properly: his eyes slitty, a sheen of sweat across his pretty face, and very pale for him – despite the strange markings across his cheekbones.

‘I didn’t eat any chicken,’ Zach mumbled. ‘But I feel really weird too, Mum.’

‘Did you nick some wine? Or some beer?’

‘No, Mum, I swear.’ He was well enough to sound indignant.

‘It’s better if you just tell me, Zachy.’

‘No, we didn’t drink anything!’ He was vehement. ‘Only Coke, and some of that disgusting energy drink Ceci had.’

‘OK, let’s get you back to the tent too.’ I pulled him up. ‘You feeling all right, Willow?’

‘Yes, thank you, Mrs March.’ The girl nodded gravely, her eyes huge, feet in a ballerina’s first position as she leant against a tree trunk as slim and graceful as her, her face as bare and clean as earlier. ‘I don’t eat meat. I’m just really worried about these guys. Can I do anything?’

‘No, you’re fine, love. Where’s your little brother?’

‘I dunno.’ Willow shrugged elegantly. ‘Think he went to bed ages ago. He’s only young. I’ll go and check.’

Melissa had managed to get Ceci around the campfire and to the tents without too much fuss, it seemed, but by the time I arrived with Zach, Willow having gone to find Beau, Rebekah was semi-hysterical about something, a half-empty Tupperware box of brownies in one tiny hand, her phone in the other.