Beth knocked on Dr Hewson’s office door and waited for a response. She could hear a voice coming from inside the room but couldn’t make out any words. There was the clatter of a telephone handset being dumped into its cradle and then Dr Hewson’s door swung open and a head of curly hair appeared. ‘Ah, it’s you, the protégé. Come on in.’

Beth gave an awkward smile at Hewson’s description. She didn’t want to be anyone’s protégé, she wanted to be her own person. At the same time, it was a flattering thought that an experienced DI like O’Dowd was mentoring her. On the other hand, perhaps the doctor wasn’t being entirely flattering, given Beth knew his relationship with O’Dowd wasn’t the friendliest. Nevertheless she decided to accept the comment as a compliment.

‘Enough with the flattery. DI O’Dowd said you wanted to speak with one of us.’

‘Not just speak, show.’ He reached behind the door and produced a lab coat. ‘Come with me.’

As she followed him to the lab, she tried to find out what he was going to show her, but Hewson deflected all of her questions with a polite, but infuriating, ‘wait and see’.

He guided her to a bench and told her to wait a moment. Beth watched as he opened a refrigerated cabinet and pulled out a tray.

When he laid the tray on the bench, she saw there were four different versions of the sliced-open trachea she’d seen during Angus Keane’s post-mortem. Each was positioned next to a label. Going left to right they were: ‘Woman 1’, ‘Woman 2’, ‘Angus Keane 3’ and ‘Man 4’.

‘What am I looking at? Or should I say, for?’

‘Patience, DC Protégé, patience.’ Hewson pulled out another stainless-steel tray and laid it beside the first. It contained two longer versions of what looked to be tracheas. ‘The ones in the first tray are the tracheas, the second tray holds Man 4’s oesophagus and a sample one from a non-victim.’

‘We’ve identified Man 4. His name was Nick Langley.’

The tattoo had been referenced as identification and while there was no doubt Man 4 was Nick Langley, his wife would still have to make a formal identification.

The sample labelled ‘Woman 1’ was half the length of the others and had pieces missing where animals had feasted. The other three were similar in size, but she didn’t see a lot of differences until she took a deep breath and bent over for a closer inspection.

A part of Beth knew Hewson was testing her, and it was this knowledge that kept her leaning over the two trays until her back ached.

She looked at the facts. Woman 1 had a scorched trachea. Woman 2 only had scorching on the upper part of the trachea. Angus Keane’s trachea showed worse burning than either of those two, while Nick Langley’s trachea was even worse. In one or two places the fire had burned holes which allowed her to see the polished stainless steel of the trays beneath.

None of it made sense to her and she couldn’t see what the doctor’s point was. Rather than admit defeat, though, Beth kept looking at both trays until her mind interpreted what her eyes were seeing. Back and forth she gazed until she made a connection.

She straightened up and resisted the urge to massage her lower back. ‘Correct me if I’m wrong here, but are you trying to tell me that the killer has been experimenting with the fire breathing for his dragons?’

As soon as she’d verbalised her theory, Beth felt stupid. Only a handful of people knew the dragon theory, and it was by no means something everyone agreed on.

Hewson’s face was impassive. ‘What makes you say that?’

His question was a double-edged sword. Either he was of the same thinking and wanted her thought processes explained, or he was mocking her and seeing just how long she’d keep digging herself deeper.

She didn’t believe he was the type of person to mock her, so after a deep breath, she opened her mouth.

‘The first woman’s burns look to be lesser than those of the others. In fact each victim shows more fire damage to their trachea than the one before.’ Beth looked at Hewson’s face again but saw no indication of whether she was right or wrong. She’d come too far to stop now. ‘He’s trying different things to see which burns the best. Not only has he been using an accelerant, but it looks like he’s been putting more of it into each of the victims. Am I right?’

A smile creased Dr Hewson’s face. ‘You would indeed be right. At least with most of your theory. Woman 1’s death was not a pretty one. When I examined what was left of her lungs and stomach, I came to the conclusion that the accelerant in her stomach, which for the record was petrol, poisoned her. I hate to say it, but she would have had a slow agonising death until dehydration overwhelmed her.’

Beth reeled at the thought of the poor woman, abandoned to die in that foetid cellar. Her throat ruined by fire. Every breath filled with agony as the poison attacked her body. Not only would her death have been excruciating, but she’d have felt her strength fading. Try as she might, Beth couldn’t help but hope the woman’s injuries had caused her to pass out so she didn’t experience either the pain or the horror of her last hours of life.

‘What about the others?’

‘My best guess is that the killer put too much petrol into Woman 2. Her lungs were saturated with the stuff and I’d say that she was technically drowning when he put his match to her. There would have been a huge puff of flame but it wouldn’t have travelled far inside her. She’d have died instantly as the fire would have burned all the oxygen in her mouth and throat.’ He leaned forward and assessed her with a careworn expression. ‘Not a good way to go, but better than her predecessor’s by a long way.’

Beth stepped away from the bench and put her back against a wall. The room was in danger of spinning as she contemplated the women’s horrific deaths in the dingy cellar that had almost taken her own life.

The pathologist gave her a couple of minutes to pull herself together, then walked across and stood in front of her. ‘You ready to continue?’

Beth nodded and let Hewson lead her back to the bench.

‘Do you see this?’ He used a pen to point to the pair of oesophagi. ‘Man 4’s, sorry, Nick Langley’s, is charred away whereas the unburned one is in good order. This is wrong. The epiglottis wouldn’t normally allow a fire to travel down an oesophagus. However, his was all but burned away. I’m not sure how, but it looks as if there was substantial burning that went on after he died.’

‘How could that have happened?’

Hewson turned from putting the trays back into the chiller and stood in front of her. ‘C’mon, DC Protégé, you can have a seat in my office while I tell you the rest of my findings and my suspicions.’

With a mental girding of her loins, Beth pushed herself off the wall and trailed behind the doctor as they walked back to his office.

It had been kind of Hewson to not comment on how she’d reacted. Instead of asking if she was okay, he’d recognised that she wasn’t and had offered a distraction, a way out. There was little doubt in her mind that he’d seen many different reactions to his work over the years, but he’d managed hers with compassion and understanding. If asked, she’d have guessed that he’d have been the type to point her to the ever-present sick bucket, or worse, hand her a mop if she didn’t make it to the bucket.

His actions proved to her that people should never be judged until there was enough information to make an accurate assessment of their character. She’d had him down as a grumpy and thoughtless man and had been proven wrong.

‘Take a seat.’ He pointed at the plastic chair to one side of his desk.

Beth sat down and glanced round the office. It was pretty much as she’d expected it to be. There was a whiteboard bearing names in different colours, detailing his schedule, a filing cabinet and a few shelves that were laden with medical textbooks.

A calendar hung on the wall beside his desk and its picture was of York Minster. There was the obligatory photo frame on the desk alongside the telephone and a computer screen.

Though it was tidy, the office displayed the signs of being well used.

‘What else did you find?’

‘After coming to the same conclusions you’ve just reached, I consulted with a colleague in Manchester. She’s a specialist in burns, both pre- and post-mortem. I told her what I found and she agrees with our assessment. She’s drawn up a database of burns received from various accelerants and has consented to give me the benefit of her expertise. I’ve taken cross-section photographs of each trachea and sent them to her. She will examine them and then give her considered opinion on each one. I don’t know how much use it’ll be for you, but it may just give you a clue, or better, some evidence you can use.’

‘That’s very thorough of you, doctor.’

‘We have to be thorough. The dead deserve answers every bit as much as the living.’

‘What you said before, about Nick Langley’s epiglottis being scorched, have you any ideas on that?’

‘One or two. Do you have any yourself?’

Beth had some ideas, but she didn’t like them. If they were right, the implications for the victims were horrific. ‘I may be wrong – part of me hopes I am – but it seems to me that he’s learning as he goes. His first victim had the least burns, which suggests that he didn’t use enough accelerant to get his desired effect. That he’d more or less drowned Woman 2 with the stuff backs up this theory.’ Beth lifted her eyes from the floor to look at Hewson. ‘Would I be right in saying that it was only a lack of oxygen which prevented the accelerant from exploding inside her?’

‘You would. When I tested her organs, they were all showing signs of poisoning from the petrol. The two men – what are your thoughts regarding them?’

‘Horrific deaths. Agony. Calculated. Experiments.’

Hewson’s bushy eyebrows twitched as the words tumbled from Beth’s mouth. ‘Interesting that you used the words “calculated” and “experiments”. Can you expand on your thinking?’

‘Angus Keane had worse burns than Woman 2, so that suggests there was less accelerant used, but what was there seems to have burned better.’ Beth leaned back in her seat and closed her eyes in thought. ‘What if more accelerant was added after the first flames died out? You know, either poured or squirted into his mouth and then lit, would that cause the burning you found?’

Hewson rested his elbows on the desk and steepled his fingers beneath his chin. ‘That’s what I was thinking. I’d even suggest he could have been using something like one of those plastic spray bottles to deliver the petrol. I’d say he only stopped after his victim’s heart gave out. For Man 4, on the other hand, the killer didn’t stop; I’d say that he kept going long after the poor bugger died.’ Hewson slid one of his desk drawers open, reached inside and pulled out an evidence bag. ‘I found this block of wood jammed between his teeth. It would keep his mouth open so that more petrol could be sprayed or poured in. The trachea was so badly burned that there’s no way our victim would have been able to breathe. He’d have died of suffocation due to a trachea that was either blistered or punctured.’ Hewson closed his eyes for a few moments. ‘Like the others, his death would have been inevitable and a release. However, I do think you’re right about the killer experimenting. He’s refining his methods to ensure the fire is breathed for longer.’

Beth tried not to revisit the cellar in her mind, did what she could not to picture Nick Langley repeatedly breathing fire. Not now that she knew the horrors that had taken place in there.

As a distraction from her thoughts, she fired more questions at Hewson. ‘What else do you have to tell me? Can you make a more informed guess as to how long the bodies were in that cellar?’

‘My initial impression was wrong. Woman 1 had been in there at least four months, but not more than eight. I’ll need to check some reference books, but I should be able to narrow that window down for you. Woman 2 was around four weeks give or take a day or two. Nick Langley was very recent. I’d say he was in there no longer than twenty-four hours.’

‘That ties in with what we’ve heard from his wife.’

‘That still means you’ll have to do two sets of dental records and DNA in the hope of getting a match. Dowdy won’t be pleased about her budget.’

Beth ignored the jibe about O’Dowd’s budget. Her mind was focussed on the various lengths of time the victims had been in the cellar. Now they had some hard facts to work with, they could focus their investigation into the victims’ identities with more accuracy, and once they knew who the two women were, could start looking at links between the victims. Furnished with an idea as to when the two women had died, they could narrow down the number of potential victims by using the missing persons’ reports.

‘What else have you got for me?’

‘That isn’t enough?’ Hewson raised an eyebrow, so Beth put a stern look on her face. ‘Okay. Judging by her teeth, Woman 1 was in her fifties. There were no distinguishing marks on what was left of her and all of her joints were her own.’

Beth understood why Hewson commented about the woman’s joints being her own. Hip and knee replacements all had serial numbers that could be used to identify the victims.

‘What about Woman 2?’

‘I’d say mid-twenties. No distinguishing marks. She was in good health and when I checked her internal organs, other than the damage wrought by the killer, I found them to be in good condition. Her muscle tone had obviously degraded after death, but from what was left, I’d say that she kept herself in shape, but I wouldn’t say that she was obsessed with exercise.’

Hewson bent down and scratched at his ankle.

‘What about the wings? Were they attached with surgical glue again?’

A nod.

‘Where are they?’

‘In evidence bags ready for you to take with you.’

Beth gave a polite grin. ‘I should have known, shouldn’t I?’

‘You should indeed.’ Hewson pointed at the bags. ‘I had a wee look at the wings; I’d say the canary, parrot and crow were from birds that he’d killed for the purpose, but I’m no expert. However, the bird of prey’s wings were different. They had a kind of lustre to them as if they’d been treated with something.’

‘Do you mean a lacquer? The kind of thing a taxidermist might use?’

‘I do and I don’t. Taxidermists soak their charges in acetone to preserve them. The wings are being tested as we speak and I am confident the results will be positive.’

This fitted with what Beth had been thinking on the drive up from Penrith. Eric’s suggestion that the easiest way to get the wings of a bird of prey was to use a stuffed bird made sense on every level.

‘Did you get anything from their bloods?’

‘Nothing from the women, but Nick Langley’s blood shows traces of flunitrazepam.’

Beth cast her mind back to her training. ‘That’s Rohypnol, isn’t it?’

‘Indeed it is.’

‘That explains how the killer got his victims to go down to the cellars. How he got them to stand still while he tied them up and attached the wings to their bodies.’

‘It does.’ The smile faded from Hewson’s face. ‘This case is affecting you. I can see it’s already changed you a little. You got upset earlier and it was nothing to do with controlling your gag reflex. If you have a bottle of wine in your fridge, do yourself a favour when you get home, leave it there. Too many good coppers start with a glass of wine or a tin of beer, only to end up borderline alcoholics. Don’t let that happen to you. Knock seven bells out of a punchbag, or go somewhere you can scream and shout at the injustices of life without anyone seeing or hearing you, but don’t get into the habit of using alcohol to mask the trauma. Trust me.’

‘Thanks for your concern, but don’t worry about me.’ Beth jabbed a finger at her left cheek. ‘I didn’t turn to drink when this happened, and I won’t now.’ She rose to her feet. ‘If you’ll let me have those wings for evidence, I’ll leave you to carry on with your day.’

Even as she marched back to her car, Beth was feeling guilty for the way she’d snapped at Dr Hewson. She knew her overreaction was due to how close to the truth he’d come. The bottle of wine in her fridge would have been opened tonight. But after what he’d just said, there was no way she was having even one glass.