Aaron nodded. It was very encouraging. Perhaps he wasn’t so difficult after all.

Then an idea struck him. ‘We could catch them and put them in a tank,’ he said. ‘And we could chop off their heads and see if they die.’

Or perhaps there really was something wrong with him.

I talked to my class about headless cockroaches after recess. It seemed to go down well, though I worried about giving Luke and Chloe nightmares. Everyone laughed when I said that cockroaches have three knees on each leg.

By lunchtime half the kids wanted pet cockroaches, and no one was teasing Aaron about his sandwich. In fact he was asked to come on a roach-hunt with George and Oscar. The hunt didn’t last long; it ended in a squabble that saw Aaron throwing bags around. But I sensed a difference in him. He seemed more engaged. For the rest of the afternoon he was fairly cooperative, though he hurled a book at Caleb and kept stabbing his playdough with a pencil while everyone else was making animals.

When Joyce came to pick him up after school, I was able to tell her with perfect honesty that he’d had a much better day.

‘And tomorrow he’ll show everyone how to make a papier-mache pig. Won’t you, Aaron?’ I waved at Beth as she steered Amber out of the room.

Aaron didn’t answer. He was staring at the floor, his hand caught in his grandmother’s strong grip.

‘Well, that’s good.’ Joyce was in strangely high spirits. ‘I have to say I’m surprised he’s been behaving himself, after what happened this morning.’

I had to think for a moment. Then it clicked.

‘Gail made Aaron his replacement sandwich at lunchtime. She rang me afterwards,’ Joyce went on. ‘It’s disgusting. This poor mite is living in filth on the weekends. I’m going to call Child Protection.’

The triumph in her voice was chilling. I cut a glance at Aaron, who was hanging his full weight off her, dangling like a dead fish on a line. Joyce didn’t seem to notice. She was too absorbed in Krystal’s failings.

‘That woman is a health hazard,’ she said, then flashed a smile at Dixie, who was passing with Oscar in tow. During first term I always asked parents to collect their kindy kids from the classroom; it was safer that way. ‘I’m going to need a written report from you,’ Joyce added. ‘I want you to say there were roaches in Aaron’s lunchbox.’

Something was wrong. I could feel it. ‘How did you know about the roaches?’ I asked.

‘Gail told me.’

‘But I didn’t tell Gail.’ I’d been careful not to.

‘Well, the kids must have been talking in the canteen. I heard Phoebe mention it a few minutes ago.’ Joyce frowned. ‘I hope you aren’t trying to keep it a secret?’