I can’t even speak I’m so out of breath.

Mum shuffles to the doorway in her dressing gown. She looks really tired even though she’s been in bed for weeks.

‘Are you OK, love?’ she asks.

I try to work out in my head how to explain to them what just happened. I always tell Mum and Dad everything, even the bad stuff, even the scary stuff, even the silly stuff. I open my mouth to tell them about the voice I heard in the woods. Then I realise how utterly ridiculous and stupid it sounds; they’ll just say my imagination’s running away again. I close my mouth, because even if they did believe me they’d only worry and then they’d probably cancel my birthday camping.

‘Charlie?’ Dad already sounds worried.

‘I’m fine,’ I finally answer.

‘O … K … ’ says Mum, drawing out each syllable and raising one eyebrow.

‘I’m fine,’ I say again with a pretend smile, remembering last summer when I told my mum about the leech Beaky thought she saw in the river and we all got banned from swimming right through the holidays.

‘Are you OK?’ I pant at her. ‘No baby yet?’

Mum puts her hand on her utterly massive belly and rolls her eyes. ‘Not quite yet,’ she says. Dad laughs. Mum doesn’t.

She looks me up and down, then shakes her head wearily. ‘Charlie Merriam, you are absolutely filthy! What have you been doing in that forest?’

‘Sorry, Mum,’ I say, knowing she doesn’t really want an answer. I wash my hands and glance at the black-and-white baby scan stuck to the fridge. The baby looks like a little alien, its head almost the same size as its body, its arms and legs so small and wheedly they look more shrimp-ish than human.

‘Hello, Little Big-Head!’ I whisper to the picture, like I always do.

‘Dinner’s ready!’ says Dad.

Mum lowers herself into the chair and sighs at me.

‘Always late and always filthy,’ she grumbles.

‘That’s Charlie’s motto, don’t you know?’ says Dad chirpily as he brings the bowls of spag bol over to the table.

‘Wild thing!’ he chuckles, ruffling my hair.

A smile flickers across Mum’s face.

‘We used to call you that when you were little, Charlie.’

‘I know, I remember,’ I say, smiling back.

‘Some things never change,’ says Dad, twirling up a forkful of spaghetti. Over his shoulder I stare at the scan of the alien baby, curled up like a prawn, waiting in the dark, getting ready to be born.

I slurp up a worm of spaghetti, licking the sauce from my lips. For as long as I can remember I’ve wished for a brother or a sister, and now my wish is nearly really actually about to come true. Excitement flutters in my chest and I grin so wide I can feel my ears hum.

‘Maybe lateness runs in the family,’ I say, nodding at Mum’s belly. And even Mum laughs this time.