Billie puts her magnifying glass to her eye and leans in close to study the netting over the strawberry patch. It is propped up on a bamboo frame and pegged neatly to the ground all around the plants.

‘Hmmm. I can’t see any holes in the netting,’ she murmurs. She writes this fact down in her little book.

‘Can I have a go with the magnifying glass?’ Jack asks Billie. ‘I haven’t had a turn with it yet.’

‘Sure,’ says Billie, and she hands it to him. Then she takes the camera out of its case and begins snapping pictures of the strawberry patch instead.

Mika and Alex crawl around the edge of the strawberry patch looking for clues.

‘Hey, look at this!’ says Mika.

The others rush over to see what she’s found. There, caught in the net, is a small brown feather. Billie takes a photograph of it.

Jack studies it through the magnifying glass. ‘Well, it’s not a magpie feather, that’s for sure,’ he says. ‘If it was a magpie it would be black and white.’

‘It’s probably a mynah,’ says Alex, importantly. He’s the one who knows the most about birds. Birds and maths are his specialty. ‘But if a bird took the strawberries, how did it get them through the net? Your mum says it hadn’t been touched, Mika.’

‘That’s true,’ says Mika. ‘But maybe its beak was small enough to poke through the holes in the net?’

Jack pokes his finger and thumb into a hole in the netting.

He takes hold of one of the pale unripe strawberries that the thief has left behind. Then he tries to pull it back through the hole in the netting. He shakes his head. ‘No. It won’t fit,’ he says. ‘I can poke my fingers through, but the strawberries are too big to pull back out through the holes.’

‘Besides, birds make a big mess,’ says Alex. ‘If it was a bird that had eaten the berries there would be lots of strawberries with holes pecked in them.’

‘And bird poo,’ Billie adds, giggling. She keeps snapping photos as she talks. ‘There’d be poop all over the net, too.’

‘I think it has to be a person,’ Jack decides. ‘How else could all those strawberries have been stolen without the netting being moved? Only a person could lift up the netting and put it back again.’

‘I agree,’ Mika says. ‘That’s exactly what I thought!’

‘Well, I don’t have any ideas,’ Alex says, stepping back and taking off his glasses to clean with his T-shirt. ‘I mean, how can we possibly find out who stole the strawberries? They’ve probably eaten them by now anyway. As Billie said, it’s not like it was Mrs Okinawa’s jewellery that got stolen!’

‘We can’t give up yet!’ Mika says. ‘What if it happens again?’

‘Look, there are all these little baby strawberries growing now,’ she adds. ‘What if someone comes to steal them just when they get ripe, too? It’s not fair!’

‘Mika’s right!’ Billie says, putting her hand on her friend’s shoulder. ‘We’ll find out who did it, don’t worry. I say we start by interviewing the neighbours. See if they saw anything or suspect anyone.’

‘We can’t just go around to people’s houses and ask if they saw a strawberry thief,’ Jack says.

‘Why not?’ says Billie.

‘Well, we’re supposed to be undercover, for one,’ Jack says.

‘And we don’t want the strawberry thief to know that we’re looking for them,’ Mika adds. ‘We need to be careful.’

‘True,’ says Billie frowning. She rubs her forehead.

‘I know!’ she says, grinning. She has had a super-dooper idea. ‘The recycling posters we made in art! We have to stick them up around the neighbourhood, don’t we?’

The others nod.

‘We should ask Alf if we can put them up in his shop,’ says Billie, ‘and while we’re there, see if we can find out some more information. He knows everyone around here.’

‘That’s a great idea, Billie!’ says Mika, looking happy again. ‘Let’s go there tomorrow afternoon.’

‘Yes, let’s. Bring your posters. Meanwhile, I’ll upload these photos this afternoon at home and let you know if I find any more clues,’ Billie says, tapping her camera. Then she gives Mika a cheeky smile. ‘I think there’s just one more thing we need to do here.’

‘What’s that?’ says Mika.

‘Go inside and eat some of your mum’s snacks.’ Billie giggles. All this talk of juicy strawberries is making her hungry!