He was a little brusque in the morning, and as the fog of sleep lifted, she knew why. He wasn’t in the huff about last night, or even the past six weeks. It was the future that was bothering him. Drew always looked at the long-term view, and he didn’t like what he was seeing.

In the shower that morning, Catherine thought about what she ought to say to him, maybe tonight if he wasn’t home too late. She’d apologise for last night, acknowledge the situation. They’d had a lot of bad luck, she would say. She would joke about it, tell him that they were like the IRA: they only needed to be lucky once. Or at least that they couldn’t be unlucky all the time.

But were they just unlucky? she asked herself. Truth, girl. Truth.

No. And it wasn’t just a lack of sex that was bothering Drew about last night. It was what lay behind it, what they might have got away from on holiday but what would always have been waiting for them upon their return.

Catherine had vowed to him that she wouldn’t become a stereotype: a senior police officer consumed by her job, slowly alienating her spouse. And on the whole, she wasn’t. Most of the time there was balance in their lives, and they were a normal, functioning, loving family. She wasn’t obsessed by cases, she wasn’t a workaholic and she wasn’t drinking away the fears, horrors and regrets every night. But there was no getting away from the fact that it was a demanding and unusual job, witness on a regular basis to the worst days of other people’s lives, and dealing with the worst deeds of the worst people.

It waxed and waned. There were times when it had a cumulative effect, but rather than alienate her family, those were the times when having Drew and the boys helped her keep it at bay. There was something else, though. Drew had learned to recognise its advent at earlier and earlier stages, but was as powerless to stop it as he was to comprehend it. Catherine regretted the former impotence but was enduringly grateful for the latter.

‘There’s this dark place you go,’ he told her. ‘You’re angry on the road to that place and you’re unreachable when you get there. But what’s hardest is you’re numb for days afterwards.’

He had recognised the anger last night, and so had she. Other people could see it too.

You wanted it too much …You hate these people.

Moira Clark had recognised it, as had Graeme Sunderland. Not to mention Cal O’Shea, and Catherine really didn’t want to spend time pondering what else the pathologist had noticed.

They all saw it but none of them understood its true nature.