She turned back to the dog. ‘He’s lucky, isn’t he, Humphrey? He gets here an hour later than he promised and he still gets a nice drink. And you and I have to drink water. What do you think of that?’

Grace felt awkward suddenly. She seemed in a slightly distant mood.

‘It’ll go down nicely while I’m waiting for the champagne to chill!’ he said, trying to placate her.

He showed her the bottle.

Examining the label while continuing to tease Humphrey, she said, ‘Detective Superintendent, do you have wicked designs on me tonight?’

‘Very wicked!’ he said.

‘You know I shouldn’t drink.’

‘I checked on the Internet. The new thinking is that the occasional glass doesn’t do pregnant women any harm.’

‘And two?’

‘Two would be even better. One for you, one for the Bump.’

She grinned, then looked down and patted her stomach. ‘What a thoughtful daddy!’ she said, mocking.

Grace slung his jacket and his tie on to a sofa, then put the bottle into the freezer and opened the fridge door. A martini glass, filled to the brim, with an olive on a stick, sat there. He took it out, carried it through into the living room and drank some, then sat down on the edge of a sofa. The alcohol hit him like rocket fuel, giving him an instant lift.

Humphrey let go of the sock and bounded towards him in a series of short hops.

‘Hey, you!’ He knelt and stroked the dog, which immediately responded by biting his hand playfully. ‘Ouch!’ He withdrew it.

Humphrey looked at him, then jumped up and bit him again.

Holding his martini clear, he said, ‘Fellow, you’ve got sharp teeth! You’re hurting me!’

‘Do you know what my father says about martinis?’ Cleo said.

Humphrey ran back to the sock, tore it free from Cleo and began shaking it furiously, as if he was trying to kill it.

‘No. What?’

‘Ladies, beware of the dry martini, have two at the very most. For with three you will be under the table – and with four, you will be under your host!’

Grace grinned. ‘So what does he say about vintage champagne?’

‘Nothing – he’s usually off his face with martinis before he gets to the champagne!’

‘I’m looking forward to meeting him.’

‘You’ll like him.’

‘I’m sure,’ Grace said, not at all sure how her posh father would take to a humble copper.

He sipped again, and now the sharp, dry alcohol was really kicking off inside his head. Then his phone rang, again. Nodding an apology to her, he tugged it from his jacket.

‘Roy Grace,’ he answered.

‘Yo, old-timer!’

It was Glenn Branson.

‘Hi,’ he said. ‘What do you want?’

‘Is this a good moment?’

‘No,’ he said. ‘What’s up?’

‘It’s OK,’ the DS said. ‘Just wanted to talk to you, about Ari.’

‘Can it wait until the morning?’

‘Yeah, tomorrow. No worries.’

‘Are you sure?’

‘Tomorrow’s good,’ Glenn said, sounding terrible.

‘Tell me?’

‘Nah, tomorrow’s fine. Have a good one!’

‘I can talk.’

‘No. No, you can’t. Tomorrow’s good.’

‘Listen, mate, what is it?’

The line went dead.

Grace tried to phone his friend back, but got straight through to voicemail. He tried his own home number, in case he was there, but that went to the answering machine after eight rings. He jammed his phone into his trouser pocket, then knelt down.

For several minutes Cleo continued playing with Humphrey, again barely acknowledging his existence. Then, after a while, tiring of the game, she let go of the sock. Humphrey dragged it over to the beanbag that was his bed and continued to wrestle with it, snarling and yapping, as if he was fighting a dead rat.

‘Want to eat something?’ Cleo asked. ‘I made one of your favourite meals. Just in case you deigned to turn up.’

She had chosen almost exactly the same words as Sandy. Sandy used to get angry at the hours he worked, and especially on the occasions when he was called out in the middle of a meal with her.

‘Hey!’ he said. ‘What do you mean by that? In case I deigned to turn up!’

‘You’re the boss man,’ Cleo said. ‘You could be home on time if you really wanted to, couldn’t you?’

‘You know I can’t. Come on, let’s not have an argument about it. I’ve got three young murdered teenagers and a lot of people wanting answers. You’ve seen the kids – I want to find out who did this, and fast, before it happens again. And I have a ton of people on my back wanting answers before Christmas. Me included. I have to give it all I’ve got.’

‘I get people brought into the mortuary every day, and I give them and their relatives all I’ve got. But I manage to keep a separate compartment for my life. You don’t do that, Roy. Your work is your life.’

Feeling that he was pedalling in a vast, dark void, Grace said, ‘When you’re on call, you have to go out – sometimes 24/7 – don’t you?’

‘That’s different.’ She shrugged and gave him an odd stare.

Grace felt a sudden stab of panic. He took a long sip on his drink, but the alcohol had stopped working. For the first time since they had started dating, she seemed a stranger, and he was scared that he might be losing her.

‘It’s always going to be like this, isn’t it, Roy?’

‘Like what?’

‘Hanging around, waiting for you. You’re in love with your work.’

‘I’m in love with you,’ he said.

‘I’m in love with you too. And I’m not stupid enough to think that I can change you. I wouldn’t want to change you. You’re a good man. But…’ She shrugged. ‘I feel very proud to be carrying your – our – child. But I worry about what kind of a father you might be.’

‘My father was a police officer,’ Grace said. ‘He was a terrific dad to me. I was always very proud of him.’

‘But he was a sergeant, wasn’t he?’

‘What’s that supposed to mean?’

‘Shit, I need a drink. How long before we can open that bottle?’

‘Maybe another ten minutes?’

‘I’ll get supper ready. Can you take Humphrey out on to the patio? He needs to do a pee and a dump.’

Grace dutifully took the dog up on to the roof garden and walked him around in circles for ten minutes, during which Humphrey did nothing except nip his hand several more times. Then, when he let him back indoors, the dog trotted down the stairs, peed on the living-room floor, then squatted and proudly delivered a massive turd on a white rug.

By the time he had cleaned up the mess, the Roederer Cristal was perfectly chilled. Two bowls of prawns, diced avocado and rocket salad were laid out on the small kitchen table. He pulled two crystal flutes from a cabinet, opened the bottle as carefully as if he was tending to a baby, then poured it.

They clinked glasses.

Cleo, seated at the table, looked stunning. So beautiful, so vulnerable. It was utterly incredible to him that she was carrying their baby. She took a tentative sip, then closed her eyes for a moment. When they opened again, they were sparkling, like the drink.

‘Wow! That is amazing!’

He stared into her eyes. ‘Look,’ he said, ‘I know I haven’t yet met your father, and there are protocols that need to be observed in your world – but – Cleo – will you marry me?’

There was a long, agonizing silence, during which she just stared back at him with an unreadable expression. Finally she took another long sip, then said, ‘Roy, my darling. I don’t want this to sound -’ she hesitated – ‘sort of weird or anything, OK?’

He shrugged, having no idea what was coming next.

She twisted the glass in her hand. ‘I just thought to myself that if you proposed to me, one day, because I was pregnant, I would never marry you.’ She gave him a helpless, lost-child look. ‘That’s not the kind of life I want – for either of us.’

There was an even longer silence. Then he said, ‘Your being pregnant has nothing to do with this. That’s just a very big bonus. I love you, Cleo. You are the most beautiful person, inside and out, that I’ve ever been lucky enough to meet in my life. I love you with all my heart and soul. I will love you to the ends of the earth and back. And more. I want to spend the rest of my life with you.’