On the way back to our cars, I saw Cilla work a handkerchief – a tightly folded white square – out of her sleeve. While she thought she was unobserved, she dabbed at the corners of her mouth. Another memory surfaced: Cilla and her handkerchiefs. I recalled a day when her class was doing a gymnastic circuit. At one station, students had to perform a rudimentary hang on the uneven bars. Cilla had no hope of holding up her own weight. Her muscles started shuddering almost instantly, even while I held my palm against the knobs of her spine.

I remembered her handkerchief dropping from her pocket to the floor, and I remembered how quickly she detached from that bar to retrieve it, how lightly she landed. She gathered the handkerchief and scurried off the mat. It was the most agile sequence of movement I ever saw her make.

In the car Pete sniffed.

‘I see what you mean,’ he said.

‘About what?’

‘That woman. She’s not right. She has a real shit-eating grin.’

At that point, I thought to tell Pete the story of the poo phantom.

It happened when Cilla was in year eight. Rumours about the first incident spread with that invisible, light-speed energy they have in a school: all at once, everyone knew that someone in the D-building restrooms had, after hours, written a message in shit on the walls. A week later it happened again and an assembly was called. The vice-principal – a tall undertaker of a man who wore faded colours and had a loose, low-hanging paunch – stood on stage and through a series of euphemisms asked the perpetrator to seek help, promising complete confidentiality.

After the assembly, I asked one of the other teachers what the messages were.

‘The first said Hi,’ she told me. ‘And the second said Help.’

‘Oh,’ I said. ‘That’s all?’

My colleague gave me a wry look.

‘I guess she had to keep it short,’ she said.

Suspicion took a while to fall on Cilla, but when it did, it stuck. We never knew for sure that it was her, but as far as the other girls were concerned, she still had shit on her hands. At the end of that term she vanished. And once she was gone, she wasn’t missed.