We are lolling about on the sofa, watching my little sister Pixie's DVD of The Little Mermaid for the 379th time and sipping hot chocolate with marshmallows on top. Pixie is spellbound. She knows every scene, every word, off by heart. It is her favourite DVD of all time.

For me, The Little Mermaid is more background noise. I am busy making a list of possible Star Qualities. My teacher, Miss Moon, is very keen on everyone finding their Star Quality, which is fine if you are great at singing like my friend Willow or brilliant at dance like my friend Beth, or even really arty like my best boy-mate Murphy Malone. It is not so good if you are me.

I cannot decide what my Star Quality should be.

I change my mind about every five minutes, and unless I can settle on one thing the chances of me getting Miss Moon's ultra-cool Star of the Week prize are not looking good.

So far, today's list says:

Famous actress
Mountaineer
Ice-Cream Taster
Prime Minister

I am not sure if I am brave enough to be an actress, and there aren't very many mountains in Brightford, but I have had some practice at ice-cream tasting and I think I could be good at that. As for running the country, how hard can it be?

If I was Prime Minister, the first thing I would do is supply unlimited custard doughnuts for all schoolchildren, and then ban homework. Although some people actually like it - my big sister Becca, for example.

Becca is a kind of geek-Goth, with backcombed hair and black eyeliner and a green-fringed boyfriend called Spike who is not nearly as scary as he looks. Right now, Becca is curled up in an armchair, ploughing through endless pages of advanced algebra while listening to clashy-trashy music on her iPod.

She is very weird indeed, but not as weird as my dad, of course.

He is having some kind of a mid-life crisis and keeps on getting these terrible ideas that threaten to turn life as we know it upside down. Dad packed his job in a few months back to follow his dreams ­which are actually like other people's nightmares ­so he is usually around when we get home from school. If we are really unlucky, he will even have a special treat for us, like prune flapjacks or beetroot stew.

Tonight we should be safe, though, because it is Wednesday and that is the night Mum brings home fish and chips once she finishes her shift at the hospital. It is the best night of the week.

Today, when we got in from school, there was no Dad at all. There was just a note saying he would be back soon, which is why Pixie made straight for the DVDs and I made straight for the hot chocolate, and Becca . . . well, Becca made straight for her iPod and her homework, but there is no accounting for taste.

The DVD is just finishing when Mum comes in, shrugging off her coat and scarf. She sets down the fish and chips.

'Hello, Daizy, hello, Pixie, hello, Becca . . .' she says, and then her eyes narrow and her voice starts to rise. 'GET THAT WRETCHED GOAT OFF THE SOFA!' she yells. 'I've told you a million times!'

Hmmm. I forgot to mention Buttercup. She is my pet goat, and a very annoying boy at school called Ethan Miller gave her to me for Christmas. Sort of. It's a long story.

Anyhow, it seemed all wrong to make a baby goat sleep in the shed, especially in the middle of winter, so Buttercup sleeps in a dog basket under the kitchen table and sometimes, when Mum and Dad are not about, she sneaks into the living room and snuggles up on the sofa.

I push her off and she skitters across the carpet, one of the fluffy cushions clamped between her jaws. Little bits of fluff and chewed-up cushion trail after her, evidence of another domestic disaster.

'Daizy!' Mum wails. 'Another cushion ruined! That goat has got to go!'

'Nooooo!' Pixie, Becca and I protest. 'Please Mum . . . no!'

'Well, she can stay in the shed then,' Mum relents. 'She's a goat, not a cat or a dog! Goats chew things! Your dad's running shorts, Pixie's slippers, Becca's school tie . . .'

'I like it better like this,' Becca shrugs, flicking out the tail end of her tie and examining the frayed bits.

Pixie ushers Buttercup out into the garden and Becca jumps up and puts the kettle on and starts setting the table and I take the fish and chips and start unwrapping them, and peace is restored. Almost.

'Where is your dad, anyway?' Mum huffs, sitting down at the table and squeezing ketchup on to her chips. 'He promised me faithfully he would keep an eye on that goat!'

'He left a note,' Becca shrugs. 'It said he has important business, and he'll be back soon.'

There's a crunching of gravel on the drive outside, and the slamming of a car door. Moments later, Dad walks past the window carrying several planks on his shoulder. Mum drops her fork with a clatter.

'Whatever now?' she groans.

We run to the door, Buttercup at our heels.

Dad is unloading rolls of chicken wire from the roof rack of the car, whistling happily, and that has to be a bad sign.

'Mike,' Mum says firmly. 'What are you doing with all that?'

'Ah,' Dad says brightly. 'I'm building an ark!' My heart sinks. An ark? We have been here before, back when Dad had his crazy plan to sail round the world. I thought he'd got over all that, I really did.

'An ark?' Pixie asks. 'Like Noah?'

'Did someone forecast rain?' Becca smirks.

Mum just folds her arms and glares at Dad and he holds his hands up, laughing.

'Relax!' he laughs. 'Not that kind of ark! I'm talking about an animal shelter. I'm going to convert the shed, for Buttercup . . . and build a run round it for the chickens!'

There is an ominous silence.

'What chickens?' Mum asks at last.

Dad opens the car boot and we all crowd round. Inside is a wire crate with three big, golden-brown chickens inside, squawking loudly and fluffing up their feathers.

'Oh, Mike,' Mum says weakly. 'What have you done now?'