‘I don’t like.’ Proust lurched forward, shaking out his arms, as if suddenly aware that he’d been still for too long. He aimed his mobile phone at Kombothekra. ‘If I’d wanted a commentary on societal norms I’d have phoned Émile Durkheim. A Frenchman, Sellers, so no doubt your wife knows all about him. It’s bad enough that we’ve had that self-promoting idiot Harbard foisted on us without you turning into a sociologist as well, Sergeant. Stick to the facts and get to the point.’

None of the team had enjoyed working with Professor Keith Harbard, but Superintendent Barrow had insisted; CID needed to be seen to be bringing in outside expertise. Familicide, as some newspapers and television commentators had called it, was too sensitive and newsworthy a crime to be dealt with in the usual way. Particularly when the killer was a woman, a mother. ‘We need all the whistles and bells on this one,’ the superintendent had said. What they’d got was a fat, balding academic who bandied about the phrase ‘family annihilation’, especially when there were cameras pointed at him, and mentioned the titles of books and articles he’d written to anyone who would listen; who blatantly thought he was the mutt’s nuts, as Sellers had so aptly put it.

‘Despite what the computer diary says, most mothers aren’t willing to give up their children when it comes down to it,’ said Kombothekra. ‘And if Geraldine killed Lucy and herself-which we believe she did-that suggests she needed her daughter with her even in death. Yes, she might fleetingly have envied Cordy O’Hara, but that doesn’t mean she’d honestly have wanted to abandon Lucy. If she had, she could have done it at any time. What was stopping her?’

Leaving no pause for anyone to answer, he went on, ‘Mark Bretherick is a rich, successful man. Wealth and success equals power. It’s possible Geraldine feared she wouldn’t stand a chance of winning a court case against him.’ Kombothekra smiled anxiously at Simon, who looked away quickly. He didn’t want to be mistaken for an ally. He wished Sellers and Gibbs would invite Kombothekra to the pub now and again. That’d take the pressure off Simon, take away the feeling that he ought to be doing something he wasn’t. Sellers and Gibbs had no excuse; their unwelcoming attitude had nothing to do with Charlie. They disliked Kombothekra’s politeness. Behind his back Simon had heard them refer to him as ‘Stepford’. Sellers and Gibbs were only capable of civilised behaviour on occasions such as today’s briefing, when they feared being impaled on the Snowman’s icicle-sharp sarcasm.

‘Remember the story of King Solomon, Sergeant?’ said Proust. ‘The real mother chose to let the other woman keep the child rather than chop it in half.’ When the inspector realised that three-quarters of the team was staring at him, mystified, he changed the subject. ‘This business about women and their depleted confidence is nonsense! My wife didn’t work for years when our children were small, and I’ve never known a more confident woman. I was the breadwinner, yes, but Lizzie behaved as if every penny of it had arrived as a result of her hard work, not mine. I regularly came home at dawn after a series of scuffles with the most unprepossessing specimens our community had to offer, only to be told that my shift couldn’t possibly have been as gruelling as hers. As for the power she wields in our family, it’s frightening.’ The inspector glanced at his phone. ‘All this twaddle about women losing confidence. Would that it were true.’ His eyes met Simon’s. Simon knew they were thinking the same thing: would Proust have said what he’d just said quite so explicitly if Charlie had still been the skipper?

Simon couldn’t stand much more of this. ‘ “You”, not “we”,’ he said to Kombothekra. ‘You believe Geraldine Bretherick killed Lucy and then herself. I don’t.’

‘It was only a matter of time…’ Proust muttered.

‘Come on,’ said Sellers. ‘Who else could have done it? There was no break-in.’

‘Someone Geraldine let in, obviously. Several sets of fingerprints were found in the house that we haven’t identified.’

‘That’s standard. You know it is. They could be anyone’s-someone who came to measure for new curtains, anyone.’

‘Who else would have a motive to kill both of them, mother and daughter, apart from Mark Bretherick?’ asked Gibbs. ‘And he’s in the clear.’

Kombothekra nodded. ‘We know Geraldine and Lucy Bretherick died on either the first or second of August, probably the first, and we’ve got fifteen scientists at the Los Alamos National Laboratory in New Mexico who’ve told us Mark Bretherick was there from July the twenty-eighth until August the third. He’s alibi-d up to the hilt, Simon, and there are no other suspects.’ Kombothekra smiled, sorry to be the bearer of bad news.

‘There’s one,’ said Simon. ‘One we haven’t managed to find yet. William Markes.’

‘Not that again, Waterhouse.’ Proust slapped the wall. ‘And don’t think you can sneak that “yet” past me. “Yet”-as if you might still find him. Every conceivable corner of Geraldine Bretherick’s life has been turned inside out, and there’s no William Markes.’

‘I don’t think we should give up looking for him.’

‘It’s not a question of giving up, Simon. We’ve run out of places to look. None of Geraldine’s friends or family have heard of him. We’ve tried the Garcia Lorca Institute where she used to work…’

‘Maybe there’s a Williamo Marco on the books.’ Gibbs chuckled.

‘… and they couldn’t help us either,’ Kombothekra told Simon. ‘We’ve eliminated every William Markes on the electoral register-’

‘Maybe one of them was lying,’ said Simon. ‘It’d be easy, if no one knew he had any connection with Geraldine except the two of them.’

‘Waterhouse, what are you suggesting we do?’ Proust’s voice was slow and clear.

‘Go back over all the William Markeses. Investigate them as thoroughly as we’ve investigated Mark Bretherick. And I’d extend that to anyone called William Marx spelled M-a-r-x as well. And M-a-r-k-s, without the e.’

‘Excellent idea,’ said the Snowman, frost coating his every word. ‘Let’s not leave out Gibbs’ Williamo Marco-though it would be Guillermo, surely. And what about men called William Markham or Markey, just to be on the safe side?’

‘We can’t do it, Simon,’ Kombothekra blurted out; Proust’s verbal torture methods made the sergeant jumpy, Simon noticed. ‘We haven’t got the time or resources.’

‘Money has a way of turning up when the people who matter think something’s important,’ said Simon, trying to beat down the anger that was stewing inside him. ‘Markham, Markey-yes. Mark-my-fucking-words, Marks & Spencer, whatever his fucking name is, the man who was probably going to ruin Geraldine Bretherick’s life.’ Simon took a deep breath through clenched teeth. ‘We keep going until we find him.’

Proust’s advance was a perfect straight line. He got as close as he could, then stared up at the underside of Simon’s chin. Simon kept his eyes fixed on the board opposite him. The Snowman’s bald head was a shiny pink blur on the edge of his vision. ‘So you’re allowing the possibility that Mrs Bretherick got the name wrong,’ the inspector said in a voice that was almost a whisper.

‘She described him as “a man called William Markes”,’ said Simon. ‘As I’ve said repeatedly, I take that to mean she didn’t know him very well, if at all. She might have got his name wrong.’

‘I agree,’ said Proust, swinging round to inspect Simon’s stubble from the other side. ‘So where shall we start? Shall we first eliminate the Peter Parkers, or should we start with all the Cyril Billingtons we can get our hands on?’

‘Those names aren’t even vaguely similar-’ Simon began.

‘So a woman can be wrong about a name, and it’s up to Detective Constable Waterhouse-the all-seeing, all-knowing-to decide exactly how wrong she can be!’ Proust bellowed. Gob-bets of his saliva struck Simon’s cheek. Kombothekra, Sellers and Gibbs froze in awkward postures. Sellers’ hand, which had been on its way down now that he’d finished fiddling with his sideburn for the time being, stuck out in mid-air. The three detectives looked as if they needed to be sprayed with antifreeze. Once again, the Snowman had justified his nickname.