By the time the girls were in their early teens, Nina realised the magnitude of her mistake. More and more, she thought about Tom. She saw how one impulsive summer had changed both their lives. In her quest to be grown-up, she’d behaved like a child. She’d been dazzled by grand words and shiny promises. Apart from dropping the occasional hint to her mother, she said nothing. In the staff room, everybody complained about their partners, but it was tepid stuff. True unhappiness was quiet.

By way of compensation, she poured too much love into her daughters, trying to shield them from the worst effects of the recession. The property crash hit the Heaney family like a runaway truck. While Julian’s father lost much of his property empire, he was devious enough to hold on to several flats. Previously, their management had been handled by an employee. When this was no longer feasible, Julian became a landlord, squeezing rent from hard-up tenants, fobbing off complaints and carrying out minor maintenance. Nina thanked the stars that she’d held onto her solid pensionable job.

Over the years, Julian hadn’t always been faithful. When the girls were small, she’d tried to ignore his unexplained disappearances. It was only when the truth had surrounded her and was lapping at her feet that she’d acknowledged it. She said nothing, a silence based largely on guilt. She reflected on how she’d treated Tom and told herself that this was payback time.

A couple of months ago, around the time that Conor was shot, she’d begun to fear it was happening again. She didn’t need a rogue credit card receipt or a lipstick-smeared shirt. She just knew. This time, she wanted to find out more. So, one evening, when Julian claimed to be fixing a leaky shower in Harold’s Cross, she followed him. The surprise was that the other woman wasn’t some free-as-a-bird twenty-three-year-old. She was a thirty-something blonde who lived on the next street and whose children went to St Fachtna’s. Emer Dawson didn’t just share a name with Nina’s teenage tormentors, she had a similar air of entitlement. She was one of those women who keeps a separate wardrobe of clothes for sun holidays; a woman who talks about supper when everyone in Ireland knows it’s either dinner or tea; a woman who says her children’s names out loud – ‘Coco! Noah!’ – so bystanders can hear how tasteful they are. While those children were at school, Emer had sex with Julian.

Nina had always hated confrontation. She liked to lower her head and muddle on. Still, there was only so much that anyone could take.