As she parked outside Cumberland Infirmary, Beth took a moment to compose herself. The growling of her stomach had little to do with the breakfast she’d foregone. She was dreading the forthcoming experience; sleep hadn’t come until the early hours as her mind had thrown her mental images of Angus Keane being dissected by Dr Hewson.

Sited where it was, off Newtown Road, in Carlisle, the hospital was well above the areas of the border city which had been affected by the floods of 2005 and 2015. It was a modern building and the main atrium always reminded Beth of an airport more than a hospital.

Rather than the front entrance, today she’d be entering the back way and would remain in the bowels of the building where the mortuary, laboratory and pathology rooms were.

The hospital backed onto farmland that fell away down to the River Eden, but Beth couldn’t distract herself from dark thoughts by admiring the view due to the raised embankments which ringed the rear of the building.

Beth left two breakfast bars on the passenger seat of her car in the hope she’d still have an appetite after the post-mortem, and got out of the car. As she walked towards the entrance, Thompson’s car pulled into a parking space nearby. When he climbed out, he didn’t look as though he’d had any sleep at all.

As a professional courtesy and, if she was honest with herself, as a way to delay entering the hospital, she waited for him by the door as the beginnings of a rain shower pattered onto her head and shoulders. Thompson appeared and gave her a nod of greeting, and they went in together. His stride was a little slower than usual, which made Beth wonder if it was fatigue or reluctance that was impeding his progress.

‘Here.’ Thompson handed over a packet of mints and a small pot of VapoRub.

Beth knew what they were for at once. ‘Thanks.’ She popped a couple of mints into her mouth and used a finger to run a thin smear of the VapoRub over her top lip.

That Thompson had finally shown her a small act of kindness made her realise that he wasn’t all bad. Despite the burden he was carrying, he’d still looked out for her.

‘You ready for this?’

Beth hissed a breath out. ‘Not really, but it has to be done.’

When they entered the mortuary, Dr Hewson was wearing a faded set of hospital scrubs, complete with mask and a surgical hat.

‘Morning both.’ His tone was bright and cheerful.

Beth supposed this was a good day for him. Rather than the humdrum, he had a genuine mystery laid out on the table in front of him. He’d been granted an atypical victim to pique his interest and stretch his professional muscles.

Hewson led them into the mortuary proper. Angus Keane lay face down on a stainless-steel table which had a second deck below that Beth deduced was to catch any liquids that leaked from the corpses Hewson worked on.

Against the stark white of the room’s walls and flooring, the wings affixed to Angus’s back appeared even blacker than they had at Arthuret Hall. The harsh lighting didn’t help, and there was a chill draft as a ventilation fan sucked air out of the room with a mechanical fervency.

So far the only smells Beth had experienced were of unscented antiseptic and VapoRub. She hoped it would remain that way and the fan would remove all the puke-inducing odours. To be on the safe side, the position of a solid metal waste bin was duly noted.

Beyond the table bearing Angus Keane, there was another that held an array of surgical tools.

‘Right, let’s begin.’

Hewson switched on a Dictaphone and began to gently probe at the wings while giving a commentary of his actions. The outer parts flexed a little, but when his probe touched the stem which was attached to Angus’s shoulder blades, there was no hint of movement. Beth heard him say the wings were attached with a glue of some kind.

Hewson swapped the probe for a scalpel and used the blade to slice a circle round the glue. It took him a few minutes but he managed to free the wing from Angus’s right shoulder. He placed the wing’s stem against a clear portion of the table and scraped a few slivers of the adhesive into a test tube.

‘Here.’ He passed the test tube across to his assistant. ‘Test these for me, will you? I’m thinking either superglue or surgical adhesive.’ The scalpel was pointed at Thompson and Beth. ‘I don’t care which it is, but our friends over there will.’

The second wing took longer to remove. Once separated from Angus, Hewson laid it with the other, then started to examine the edges of the areas where the skin had been removed.

A gloved hand waved them forward. As she inched towards the body, Beth made sure breaths were only taken through her mouth. It would be bad enough puking in here; to do it so close to the body would be unacceptable.

When they got to the side of the table, Hewson again used his scalpel to point. ‘See this square, do you see how perfect it is? This isn’t some rough gouge to remove the skin, it has been done with precision. Whoever did this had a steady hand, and I’d hazard that this wasn’t the first time they’d done this.’

‘You’re right. It looks to be a perfect square.’

‘There’s one way to find out.’ Hewson replaced his scalpel with a metal ruler and measured all four sides of the square. ‘It’s 62 millimetres on each side. Let’s see just how good a surgeon our killer was.’

The ruler was placed diagonally corner to corner on the wound, then Hewson repeated the six measurements on the left shoulder blade.

Hewson’s low whistle sounded odd in the sterile environment. ‘This guy is good. Both areas are exactly the same size and one is a perfect square while the other is only a millimetre out.’ He looked up from the body. ‘I’ll be honest with you, I wouldn’t fancy my chances of replicating those cuts on a living person with the same level of accuracy.’

All of this information swirled in Beth’s head as she watched Hewson work. As much as she wanted to focus on each point, she knew she had to file everything away for a more thorough inspection later.

Right now, she had to pay attention to what Hewson was saying and doing. Questions could be asked when he was finished.

After taking a series of photos, Hewson called his assistant over and together they rolled Angus onto his back.

He looked at Thompson. ‘I presume you’d rather I concentrate on cause of death than the wounds which appear to be post-mortem animal bites.’

‘Of course.’

Beth detected a hint of impatience in Thompson’s voice, but Hewson had either missed the inflection or had chosen not to rise to it.

‘Before I open the chest, or the head, I have to first do a few preliminary checks.’

Without waiting for Thompson’s approval, Dr Hewson picked up his probe and bent over Angus’s head.

First he peered at the empty eye sockets. A pencil torch was used to illuminate the pair of empty caverns.

Beth listened as he confirmed his earlier theory that Angus’s eyes had been pecked out by birds.

Using both hands, Hewson squeezed at Angus’s head then intoned into his Dictaphone that there were no obvious blunt trauma wounds that may have caused death. His probe touched Angus’s lips and a little charred flesh rolled down the corpse’s chin and onto the table. Gloved fingers took hold of Angus’s chin and the probe was used to tease the lips apart.

Beth couldn’t help taking a little step forward when Hewson gasped. Anything that provoked such a reaction from a seasoned pathologist was of interest to her, regardless of how gruesome it may be.

‘What is it?’

Hewson picked up his pencil torch again and shone it into Angus’s mouth. ‘The inside of the mouth is every bit as scorched as his lips.’

With the pen between his teeth, the pathologist used his left hand to hold the mouth open and fed his probe inside.

A grunt and a nod were used to suggest Beth and Thompson took a look for themselves. Beth watched as her DS went first.

When he recoiled back, she took a deep breath and bent over to look inside Angus’s mouth. Every part of the inside was blackened and scorched. His tongue was covered in broken lesions. When she looked to the back of Angus’s mouth, she saw tonsils that resembled a pair of black cherries.

She took a step back and looked to Hewson. ‘His mouth has been completely burned, hasn’t it?’

‘Definitely. I should imagine his windpipe blistered and blocked his airways. That’s what I suspect was his ultimate cause of death.’ He picked up a scalpel and pointed behind her. ‘I need to check his trachea to confirm the theory. You may want to take a step back. This could be rather smelly.’

Beth added another smear of VapoRub and stood her ground. She didn’t fail to notice Thompson had retreated to the back of the room. That could be a sign of either a weak stomach or hard-learned experience. Whichever it was, she’d made her stand and to move back now would indicate a weakening of resolve. Much as she may pity Thompson’s domestic strife, there was no way she was giving him an excuse to take his inevitable frustrations out on her.

Hewson lifted Angus’s head and placed a padded bolster under his neck. Now the head was tilted back exposing the throat.

The first incision he made was a delicate one which he used to expose one of the rubbery-looking pipes in Angus’s throat. With a quick glance at Beth first, he pressed his scalpel against it until the point sunk in. With a deft movement he drew it along until he’d cut enough for it to gape open.

Again the torch went into his mouth as he used both hands to direct probes. With the tube teased open, Beth could see raw inflamed flesh which had pockets of loose skin everywhere.

When he removed the torch from his mouth, Beth listened to Hewson’s technical description of what he’d found and waited for him to stop talking before she spoke.

‘Am I right in saying that he must have breathed the fire down into his lungs?’

‘You would. This bears further investigation which will happen when we look at his lungs later.’ Hewson lifted his scalpel again. ‘But having seen the state of the trachea, I want a look at his oesophagus.’

A half-remembered biology lesson informed Beth the official name for the windpipe was trachea, and that the oesophagus was the connection between mouth and stomach. Beth prepared herself for a noxious smell as Hewson cut into Angus’s oesophagus. She watched as he opened it for inspection. It too was marked with crimson wounds and had sagging areas where blisters had deflated.

‘Jeez. What does that mean?’

He looked up at her with confusion on the parts of his face she could see. ‘I don’t know. At least, I don’t know yet. I will find out when I get a look inside him though.’

‘Isn’t it odd though? Him having burns in his windpipe is one thing if he’d breathed in the fire, but in his oesophagus, that doesn’t make any sense at all to me.’

‘Nor me. But I do know one thing, only fools and foremen comment on an unfinished job.’ His eyes twinkled. ‘You’re not a foreman, so don’t be a fool.’

‘Sorry.’

‘Don’t be sorry. Be wise. I have at least a half hour’s work to do before I open up his chest and get you the answers you want. Bugger off and have a smoke or a cuppa, or text your boyfriend, then come back in half an hour or so.’

Beth glanced at her watch. Being a single, non-smoker, all she could do was grab a cuppa. If the colour of Thompson’s face was anything to go by, he needed the cuppa more than she did.

When they got back Dr Hewson was making the first incision into Angus’s chest. Beth and Thompson both returned to their previous stations and stood without speaking.

As a precaution against any nasty smells Beth had smeared a fresh line of VapoRub onto her top lip. Thompson had done the same but his was twice the size of hers. The DS hadn’t spoken to her while they’d had a cuppa. Instead he’d sipped at his tea and nipped outside and come back with the smell of cigarette smoke hanging from him.

Such was Hewson’s focus, he didn’t speak or look up to acknowledge their return.

Beth watched as the pathologist opened the chest and picked up an oscillating bone saw. Its whine as it cut through the ribcage was akin to fingernails being dragged across a chalkboard.

When the ribs were freed, Hewson levered them back until he could access Angus’s internal organs.

‘In light of what I’ve already found, I think that I should examine the lungs and stomach first. Any objections?’

The question was asked more out of politeness than being a serious query, as Beth knew that, in here, Hewson was in charge. All the same, she turned and looked at Thompson. He gave her a tight-lipped shake of the head.

‘None.’

Hewson picked up his scalpel and, with deft movements, made the necessary cuts to allow him to remove the lungs and heart.

With the lungs, stomach and heart on a separate table, Hewson used his scalpel to slice along the length of the trachea, right to the point where it connected to the lungs. He teased the windpipe open and bent over it.

‘Interesting.’ He lifted his head and looked to Beth and Thompson. ‘Do you see this?’

Beth stepped forward and leaned in for a better view. She expected Thompson to elbow her out of the way, but instead felt no sign of his presence.

When she looked at where Hewson was pointing she couldn’t make any obvious deductions. ‘See what?’

‘The top of the trachea shows far more signs of scorching than the lower areas.’

‘Is that synonymous with breathing fire into the lungs.’

‘Correct.’

Beth couldn’t see Hewson’s face, but she heard the smile in his voice. It gave her a little flush of pleasure, and inappropriate though it was in the circumstances, she could feel her lips pulling themselves into a satisfied grin.

Hewson lifted his face from the organ mass. ‘You better stand back. This isn’t going to be terribly fragrant.’

The doctor was kind enough to wait until Beth did as she was told and had joined Thompson at the back wall.

This time his scalpel sliced open the oesophagus and carried right on until the stomach could also be peeled flat. The stomach was empty but that wasn’t what almost floored Beth. A stench that she couldn’t believe came from a human being fought at her nostrils, but she denied it entry and concentrated on breathing through her mouth while trying not to disbelieve what her eyes were showing her. The worst thing about the smell was the fact it also carried a weirdly familiar chemical tinge that she couldn’t place.

Every part of Angus’s stomach and oesophagus were laid flat before Dr Hewson. The upper areas of the oesophagus displayed blisters, charred parts and raw areas of flesh where skin had been sloughed off when the blisters had burst.

Whatever fire had burned Angus hadn’t made its way right down to his stomach, but that wouldn’t have made his death any less painful.

As Beth’s mind reeled at the agony Angus must have endured in his final moments, it kept circling back to one point. The killer had to be found. She was on the investigating team and therefore it was her job to find him. More than her job, it was her duty.

Behind her she heard the rustle of clothes and the shuffling of unsteady feet. She turned and saw Thompson heading for the door. He trailed a hand along a wall as if needing its strength to support him.

‘Well, as you’re now the senior officer in attendance, what do you make of this?’

Beth looked up at Hewson’s question. ‘I don’t know. Was some kind of burning liquid poured down his throat to kill him?’

‘It’s possible.’ Hewson used a pair of tweezers to lift a small flap of charred skin. ‘This is the epiglottis, it operates as a valve between the oesophagus and trachea to stop food and drinks going into our lungs. It’s a fraction of the size it should be. I can’t tell if he had burning liquid poured into him, or whether the liquid was put in first and then ignited. At least, not yet. From the smell of his stomach contents though, my guess would be the liquid was poured in first then lit.’

It took Beth a moment to get her head around what Hewson was saying, or not saying, as the case may be.

It was bad enough that there were wings attached to his back, but the fact he’d had his innards scorched took this to a whole new level.

‘Say the liquid was poured in first and then lit. What exactly would have happened?’

Beth could see Dr Hewson’s face was scrunching behind his surgical mask as he thought about her question.

‘If that happened, the fumes in his mouth would have combusted at once and caused the burns we’ve seen.’

‘Would the fire be drawn into his body? Would the petrol or whatever in his stomach catch fire?’

‘I’d say not. Fire needs oxygen and provided the epiglottis stayed closed, the petrol in his stomach wouldn’t ignite.’

‘So it would just stay in his mouth and throat?’

‘To a point. If the flames were still burning, he’d have drawn some of them into his lungs when he breathed in. I expect to find that his trachea and the upper areas of his lungs have blisters from burns on them.’

‘Would these wounds have killed him?’

‘It’s possible, but not likely, the blisters blocked his airways. If it was petrol that was poured into his stomach, the fumes he’d breathe into his lungs from the residue in his mouth would attack the lung tissue.’ A grave sadness overtook the doctor’s eyes. ‘The lungs would suffer chemical aspiration which would be hideously painful.’

‘What if he’d kept his mouth closed so the killer couldn’t light the petrol inside him?’

‘Nothing would happen, but that’s easily solved. A solid punch to the solar plexus would have him gasping for air. There’s no sign of a bruise on his stomach though, so I’d say maybe the killer just pinched the victim’s nose shut until he opened his mouth to breathe. Or even stuck a nose clip on him. You know, like swimmers wear?’

‘Urgh. That’s awful. You make it sound like the killer planned every detail.’

Hewson shrugged. ‘I’m just looking at the evidence. I’d suggest you do the same.’

‘Okay then. Was there any sign of a nose clip being used? Indentations on the nose, little bits of rubber scorched onto his skin?’

‘None that I noticed, but it’s possible the killer removed the nose clip once the petrol was poured in. The victim would have been coughing and choking on it, so his mouth would have been open.’

Beth did as Hewson had suggested and looked at the other evidence they’d collected, but she didn’t feel any better for it. The surgical precision with which the skin had been removed from Angus’s shoulder blades spoke of practice. If Hewson was right and a nose clip had been applied, it suggested the killer was either familiar with what he was doing, or knew a lot more than she did about the human respiratory system.

Her thoughts began to run along the lines that the killer was a doctor, or had had medical training, but with the internet, anyone could find out that information. You could learn pretty much anything with a few searches and a little patience. So far as the removed skin was concerned, a butcher or a chef would also have the knife skills needed to have done that.

Hewson laid down his scalpel and lifted Angus’s lungs from his chest. A moment later he’d split the trachea open and laid it out flat. His next cut continued on from the trachea and showed that the blistering continued into the top of the lungs.

‘Hmmm. This doesn’t look good. These burns are probably the worst I’ve ever seen on lungs and I don’t say that lightly.’ Hewson looked Beth in the eye. ‘I’ve had people who’ve died in fires show less flame damage to their lungs.’

‘What does that mean?’

‘It means you can get yourself off, lass. I don’t think there are any other key details to come without hours of tests. Plus, I need to consult a few textbooks on this one.’

‘Are you sure?’ Beth was glad when he nodded. The sooner she could get out of here, the better. ‘I know you can’t be specific yet, but DI O’Dowd is sure to ask, do you have the official cause of death yet, and how soon can you get your report to us?’

‘Don’t quote me as I haven’t finished yet, but in my professional opinion, the answer is almost certainly going to be fire-related. I’ll send you my report as soon as I’m finished and have all the test results.’