That evening before dinner, Billie takes out her secret notebook and turns to a fresh page. On it, she writes a list of names and puts a tick next to the ones they have already spoken to:

That only leaves one person: Lola. She’s the one who told everybody it was Benny who had put the leaves in Rebecca’s sandwich. She is the main witness.

‘Dinner!’ Billie’s mum calls from the bottom of the stairs. Billie locks up her secret notebook and hides the key under her pillow.

Then she runs downstairs and sits at the table. Billie’s mum is buckling Noah into his highchair. Her dad is still at the kitchen bench, finishing dinner.

‘So, how was your day, Billie?’ her mum says, as she cuts up Noah’s food.

‘Good,’ Billie says, like she always does. She is too busy thinking to come up with a better answer.

‘Anything else?’ Billie’s mum smiles.

Billie grins and tries a bit harder. ‘We’re doing posters in art,’ she says. ‘On saving the environment. We’re going to put them up around the neighbourhood when they’re finished. I want to ask Alf if I can put one up in his shop.’

‘That sounds great!’ Billie’s mum says, sneaking a forkful of food into Noah’s mouth. He frowns and spits it out.

‘I do it!’ he says crossly and grabs the fork.

Billie giggles as she watches him try to spear a piece of meat onto his fork. Finally, he just picks the food up with his hands and shoves it into his mouth.

Billie giggles as she watches him.

Just then, Billie’s dad comes to the table carrying a plate of something that looks like fat green caterpillars.

‘Ew!’ says Billie. ‘What’s that?’

‘Dolmades!’ Billie’s dad says proudly. ‘I made them myself!’

‘Doll-what?’ says Billie, peering at the strange food in front of her.

‘Dolmades,’ Billie’s dad says, picking one up and putting it on Billie’s plate. ‘Vine leaves stuffed with minced lamb and rice. Try one. They’re delicious!’

‘Vine leaves?’ says Billie. ‘What, you mean like a grape vine?’

Billie’s dad nods.

‘I didn’t know you could eat leaves,’ Billie says, suspiciously.

She picks up the little bundle and takes a nibble. Her dad is right. It is delicious!

‘Of course you can!’ Billie’s dad laughs. ‘You can eat lots of leaves. Vine leaves, dandelion leaves, nasturtium leaves, mulberry leaves…’

‘Mulberry leaves?’ Billie interrupts. Her dad nods.

‘You can really eat mulberry leaves?’ Billie says, chewing slowly as an idea comes into her head.

‘Sure,’ says her dad. ‘I probably wouldn’t eat them raw, but they’re not poisonous, like gum leaves or rhubarb leaves are.’

‘So…’ says Billie. ‘Gum leaves are poisonous, but not mulberry leaves?’

‘Uh huh,’ says Billie’s dad, putting another couple of dolmades onto Billie’s plate.

But Billie is deep in thought. She has discovered another clue!