‘No,’ says Clayton. ‘None at all. After all, they were buried inside a sarcophagus. We could date the tomb fairly accurately.’

‘Then why not keep them at the university?’

Clayton looks uncomfortable. He doesn’t meet Ruth’s eye as he says, ‘As I mentioned, there was some bad feeling about the dig.’

‘Why?’

‘Oh …’ Clayton seems suddenly completely preoccupied in adjusting his plastic gloves. ‘Waste of resources. That sort of thing.’

‘Bad feeling towards Dan?’ Ruth persists.

Clayton looks up, his plump face shocked. ‘No! Dan didn’t have an enemy in the world.’

That’s not what the police think, though. Ruth remembers her conversation with Nelson. The police think that someone killed Dan. That that someone may well be at Pendle University and may well be the same someone who is sending Ruth texts, warning her to stay away from these very bones. Well – she squares her shoulders as she takes the box from Durkin – she can’t be scared that easily. Well she can, but that’s not the point. The point is that she’s here despite being scared. She starts to lay the bones out on the examination table.

She starts to arrange the skeleton in correct anatomical order, looking for any distinguishing marks – disease, malnutrition, trauma – anything that would help her create a picture of the person who died so many years ago. At first sight the bones look to be those of an adult male, which is a relief, whatever Clayton says. They also look old, which may not mean anything. Recent skeletons are usually fairly obvious but it’s often not easy to distinguish between a body that died fifty years ago and one that has lain in the earth for hundreds of years. So many factors can affect the preservation of bones.

Clayton Henry watches her closely but does not attempt to help. After all, this isn’t his area of expertise. Durkin also stands respectfully in the background. The room is cold; it is obviously kept at a mortuary-like temperature.

Ruth starts by examining the skull, observing the pronounced nuchal crest which confirms that the skeleton is male. Then she looks at the teeth. Teeth are a forensic archaeologist’s best friend. They show signs of age, nutrition and diet. Horizontal ridges can indicate periods of arrested development such as illness or malnutrition. Teeth also carry an indelible record of the time and place when the adult teeth first erupted. Bones renew themselves; teeth do not.

Ruth looks at the upper jaw for a long time, then she picks up the lower jaw, which has become detached. This she examines for so long that Clayton Henry starts to shift from foot to foot.

‘Found anything interesting, Ruth?’

Ruth beckons him over. ‘See the teeth in the upper jaw? They’re really ground down.’

Clayton peers over. ‘Yes. Shows our bloke must have been a good age. Or else he was just a worrier.’ He laughs heartily.

‘But look at the lower jaw.’

‘What?’

‘The teeth aren’t ground down nearly as much.’

‘How can that be? Wouldn’t they grind against each other?’

‘Exactly,’ says Ruth.

‘What do you mean?’

Ruth puts the two halves of the jaw side by side on the table. ‘They don’t fit,’ she says. ‘These are from two different heads.’

*

‘I don’t understand,’ says Clayton Henry for the umpteenth time. They are sitting in a cafe next to a derelict funfair. It’s the nearest place they could find. You couldn’t imagine anyone actually choosing the cafe for anything other than convenience. The owner looks as if she lost all hope in about 1953 and the air is fuggy with chip oil and steam. Clayton, in his dark suit, looks as out of place as a food inspector. He looks sadly into his tea, which is grey with a sort of beige scum on top.

Ruth sips her coffee, which oddly also tastes of chips. ‘There are two explanations,’ she says. ‘Either there were parts of two skeletons in the sarcophagus, laid out so as to look like one body, or some of Dan’s bones were switched, either at the dig or at the lab.’

Clayton shakes his head. ‘Dan would have noticed if there were parts of two different skeletons,’ he says. ‘I mean, he wasn’t a bones expert but he would have noticed the teeth. He looked at the skull for a long time, trying to age the bones. He would have noticed.’

‘Yes,’ says Ruth. ‘He would have.’ She thinks of Dan, the star of the UCL archaeology department, and feels suddenly very angry that anyone could have considered playing such an obvious trick on him.

‘Let’s think about it,’ she says. She scrabbles in her organiser handbag for notebook and pencil. Ruth likes lists; it is something she has in common with DCI Harry Nelson. ‘Who was at the dig on the day that the bones were excavated? I assume it was done over one day?’

‘Yes. Dan was very particular about that. Every bone had to be recorded.’

‘Where are those records now?’

Clayton shrugs helplessly. ‘I don’t know.’

On Dan’s laptop, Ruth supposes, along with his notes and the novel. But there may be hard copies somewhere in the department. She resolves to look.

‘You’re sure he took the samples for testing at the dig?’ she asks.

‘Yes, I saw him take soil samples and he also put aside some teeth and small bones to be sent off for analysis. He bagged them up and put them in his car, I think.’

So the test samples will actually have be taken from the original skeleton, thinks Ruth.

‘What about photographs?’ she asks. ‘He would have photographed the skeleton when it was fully exposed, before excavation.’

‘There were official photos,’ says Clayton. ‘Taken by the county archaeologist, I think. And Dan took pictures on his phone.’

Bloody Dan, thinks Ruth. Why did he have to be so high tech? She takes photographs on digs with a digital camera but she also always does a sketch in her notebook and takes copious notes. And notebooks, unlike mobile phones, tend not to go missing. She says as much to Clayton.

‘Oh, I love technology,’ he says unexpectedly. ‘I’m a real gadget boy, just got the new iPhone 4.’

Ruth stops him before he can get into one of those iPhone conversations that their owners think are so fascinating. ‘So,’ she says, getting out her (low tech) notebook. ‘Who was there that day?’

Clayton crumples up his face in thought, looking more like a peevish baby than ever. ‘Some people from the local archaeology society,’ he says. ‘I could get their names for you. Susan Chow, the county archaeologist. I was there, and a couple of other people from the department.’

‘Who?’

Clayton takes a sip of tea, grimaces and pushes the cup away. ‘Guy was there, I think. Yes, Elaine and Guy. They were very interested in the excavation.’

‘Did you actually see Dan box up the bones?’

‘Yes. We were going to take them to the university but Guy thought …’

He stops.

‘What?’ asks Ruth. ‘What did Guy think?’

‘He thought they would be safer at the lab so he drove them there himself.’

*

When Ruth gets back to Lytham, Beach Row is deserted apart from a blonde woman walking her dog. Cathbad is out with Kate. He has left a message saying that they wanted to see the lifeboat museum, for all the world as if Kate has expressed a keen interest in marine rescue. Still, Ruth is grateful that Cathbad is prepared do so much babysitting. What’s more, he seems to enjoy it. All in all, living with Cathbad is not as difficult as she feared. Ruth hasn’t lived with anyone since Peter. Max’s weekends don’t really count, though by Sunday Ruth often catches herself looking forward to being on her own again, free to have Flint in bed with her or to watch TV in her pyjamas. But Cathbad is different. He’s not a boyfriend so she doesn’t really care how he sees her. Also, for someone who claims to be outside the normal rules of human behaviour, he’s surprisingly domesticated. He gets up early, goes for a dawn walk and then is back in time to make Ruth a cup of tea and watch breakfast TV with Kate. For the first time since Kate’s birth, Ruth is actually able to have a lie-in. And, if instead of dozing peacefully, she lies in bed worrying about Nelson, Max, Dan and mysterious text messages, then that’s her own fault, isn’t it?