‘Oh, holy fucking shit,’ Connie whispered.

The walls were alive. Frozen in time, but alive. Every inch was filled with faces staring out of Polaroids, photos, newspaper cut-outs, glossy magazine pictures. Black-and-white smiles, glances to camera, distant away gazes. Connie steeled herself against the desire simply to run inside and touch those photos, to drink in the information they contained.

‘Move in,’ she whispered.

‘What is this?’ the firefighter asked.

Connie watched the faces sharpen into focus in the monitor. ‘It’s obsession.’

Closer inspection revealed a theme. Of the thousands of faces staring out from the wall, each was female. Some might have been in their late twenties, the majority their thirties, the others in their forties but no older, each woman had a certain look. Difficult to reduce to a few words, but there was a kindness, a softness to them. Some shots had been taken in the home, others holding the hand of a child or two, maybe playing, plenty taken on beaches, or in gardens and parks.

‘They’re all mothers,’ Connie said. ‘I need you to walk along that wall. I’m looking for two specific faces. Go slowly and stay about a foot from the photos. I need a good view.’

Connie located Angela first. The shot had been taken while she was standing in a crowd of other adults, all lined up looking roughly the same way. Behind their heads, a climbing frame was just visible.

‘That’s a school playground,’ Connie muttered. ‘Look for other photos with that woman in, the one centre frame.’

The head-beam shifted left and right, then paused.

‘These?’ he asked, his fingertip in view as he pointed at a whole section.

There she was. Angela walking along the road ahead of her photographer, holding the hand of her daughter on the left and her son on the right. Angela shopping at some supermarket. Angela sleeping. Connie put one hand to her throat. Elspeth was there, too, somewhere.

‘You want me to show you the other walls now?’ he asked.

‘Uh-huh,’ she said.

Directly opposite the wall of mothers was one filled from top to bottom with girls. Connie estimated the age range to be from eight to fourteen, all happy, wholesome-looking kids, some studious, others playing sport. All picture-perfect children. The sort you could have with your loyal, sweet, faithful picture-perfect wife

Then Meggy. Coming out of school, getting into a car with her scowling step-mother. Meggy at the park, reading her book alone on a roundabout, looking wistful. Meggy’s bedroom window.

‘The other walls?’ Connie asked.