"Could we speak to your wife, sir?" Erica said to Mr Lennox.

"She just popped out for some milk," he said. "But she has her phone with her. I can give her a call." His eyebrows raised in a question.

"Please do," Erica said. "Tell her we'll meet her outside."

We trotted down the stairs and back out into the street. The late afternoon sun still had some fight left in it. Shadows dappled the roof of the pool car.

We waited on the pavement.

A couple of minutes later, a heavy woman came jogging up the road. She wasn't dressed for running. And she was carrying a carton of milk.

"I think this is our girl," I said.

We started walking towards her.

"Mrs Lennox," I said.

"Officers." She put her hand on her ample chest and breathed hard through her open mouth. Her eyebrows were over-plucked and made her look slightly startled. "How can I help?"

"It's one of your pupils," Erica said.

"Oh. Who's been up to what?"

"It's about Bruce Wilson."

Mrs Lennox laughed like a smoker.

"Why is that funny?" I asked.

"You're having me on."

"I can assure you, Mrs Lennox, that this is extremely serious."

She coughed twice and stared at us. "Call me Grace, please," she said. "Otherwise it feels like I'm at school and we don't want that. I'd have to ask you both to put your hands up before you ask another question."

"Grace," I said. "We've just spoken to Bruce's mother. Is there anything you can tell us?"

"I didn't need to run after all."

"Can you explain what you mean by that?" Erica asked.

Mrs Lennox nodded. "You'd better come on up."

7

The sitting room was full of family photos. On the walls, on the mantelpiece, on the furniture.