Outside, Anna sent Holder back to HQ with an update for Rainsford and a message saying she would follow.

In the car, she told Khosa to head back out to the burial site next to the railway.

‘What else is there to see, ma’am?’

‘Not sure yet. I may know when I get there.’

It was an enigmatic answer but the best she could offer. They’d struck lucky with identifying Jamie Carson and Brown’s confirmation that the second victim was an adult female. It was useful, but it also threw up more questions than answers. Could she, too, be a Black Squid victim? As far as Anna knew, all other victims had been teenagers. The ring, a thin band with a few stones, looked suspiciously like an engagement ring to Anna. And it had been on the right finger. Of course, an engaged woman could be depressed, even suicidal, but the broken bones in the forearm strongly suggested a violent act had been committed, not a suicide. Yet it was the card that threw her. Something, some link in the chain, was trying to forge itself, and her gut told her the site was where the answer lay. Too difficult to explain to Khosa, she simply fell into a contemplative silence. And Khosa knew her well enough not to question Anna’s pensive moods when they came to call.

They parked in the cordoned-off area. The day was bright and cold. The tents were still set up but there was markedly less activity than previously. They signed in on the scene log and Bradley, the CSM, met them as they crossed the tape.

‘Afternoon,’ Bradley said. He looked cold under his Tyvek suit.

‘You’ve found nothing else, I take it?’

‘We’ve found a few things, ma’am. Bits of plastic, water bottles, broken cups, blown paper. I doubt any of it has anything to do with what went on here.’

Anna nodded. ‘Network Rail?’

‘This site has been used for storage for years. The wooden railway sleepers were here at the time of Carson’s disappearance. But the concrete sleepers were dumped here sometime in 2009.’

‘Right, so we know the second body has been here since then at least. She must have been here when they were put here.’

Bradley nodded.

Anna walked across to the tents. To where they’d found the second body. An area of some twenty square yards behind, including the tent perimeter, showed the stone chipping to be of a lighter colour than those surrounding it: a pale footprint of where the concrete sleepers had been stored, cordoned-off by markers. She stood at the edge and looked around. The trees seemed denser here. More overpowering.

‘What is it, ma’am?’ Khosa asked. She’d put on her outer clothing and her voice again emerged from a deep cavern of faux fur.

‘Something, but…’ Anna sighed and strode back to where they’d found Jamie and repeated the exercise while Khosa followed. The only noise was the walls of the thin Tyvek tent rippling in the keen wind. Anna looked at the railway and then walked behind the tent. From there, she could look the other way, across to the rising ground and the dark fence beyond.

She called over to Khosa. ‘There, what do you see?’

‘Trees and bushes, ma’am.’

‘Further up.’

‘A fence. That’s Ryegrove, ma’am.’

Anna nodded, feeling the link slot into place. She turned away and began walking quickly back to the car.

‘What, ma’am?’ Khosa asked.

‘I’ve just remembered. When Shaw first told me about this body, first said he had something else to show me, he mentioned that the victim he’d got this information from had used a phrase. The “monster house”.’

Khosa turned her head towards the fence, her big eyes now a little wider.

Anna said, ‘And what sort of security would they have there, Ryia?’

‘High. There was razor wire on the top of that fence.’

‘And inside?’

‘Don’t know, ma’am. I’ve never been.’

‘Come on, let’s get out of this cold.’

They went back to the car, sliding in, unbuttoning coats, removing headgear.

‘OK,’ Anna said, ‘pretend you’re a member of staff in Ryegrove. How do you think you’d get from one area to another?’

‘Keys?’

‘Keys.’ Anna nodded. ‘Big, metallic, jingly things that are heavy and difficult to carry. Secure units have had a lot of money spent to modernise them. Ryegrove certainly has. So maybe they’ve changed the locks.’

Khosa frowned. ‘Changed them to…’ Her lids fell and then opened wide with pained realisation. ‘Electronic access cards. Ma’am, you’re a genius.’

---

Five minutes later, they were heading back through the lanes towards the entrance to Ryegrove. A standard North Bristol NHS Trust sign signalled the entrance to a sprawling site. After thirty yards the common access road split. On the left were the old buildings, more Grade II-listed pennant stone like the coroner’s court at Flax Bourton, now part of the University of the West of England’s Applied Sciences faculty. But Khosa took the road to the right, to a grand façade where the old house had once stood. On either side of the sandstone, two new wings spread out in an arc. Two storeys of yellow brick and render with grey slate roofs and a steel and glass entrance. Extending out on both sides of the new build was the fence. Black-coated steel, seventeen feet high.

Khosa parked in one of the bays and they headed for the main entrance. The atrium inside was airy and manned by a glass-walled reception. There was no way in other than through a turnstile inside a curved entryway.

The security guard behind the glass wore a lanyard with a photo ID. The name read Jack Morris. He looked at Anna’s warrant card and nodded. ‘What can I do for you, Inspector?’

‘HR, please.’

‘They expecting you?’

‘No.’

‘It’s easier if they come out to you, then,’ he said with a nod towards the security access X-ray machines.

‘Good idea.’

The guard picked up a telephone.

‘One question: your badge, does it also work as a key?’ Anna asked.

‘Yep.’ The guard hesitated and raised one eyebrow. ‘You’re not going to ask me if you could borrow it, are you?’

Anna snorted, ‘No. Why, have you been asked?’

‘Oh yes. That and a hundred weirder things. We get all sorts through here.’

‘No. I don’t want your badge. We’ll be over here.’ Anna pointed to some blue sofas.

They sat under some posters advertising an upcoming ‘Friends of the Hospital’ concert.

‘They use their badges as key cards,’ Anna said.

Khosa nodded. ‘But our unknown corpse could not have worked here for years.’

‘No. So that’s another question we need to ask.’

Anna watched people come and go. It looked like a lot of people worked here. After a few minutes, a man, small, neat, with a hipster beard, appeared though the security door and walked over to them. He wore a shirt and jeans and the inevitable badge on a lanyard.

‘Hi, I’m Ruben Childs, Human Resources. Can I help?’

‘We’re investigating a suspicious death, Mr Childs. So far, we have not identified the deceased. We have reason to believe there may be some link with the hospital.’

‘Really?’ Childs looked alarmed.

‘Yes. But this is not recent. We’re looking at prior to 2009. We wondered if you had anyone on file reported missing before that date?’

Childs frowned. He looked to be about the same age as Khosa. He would have been mid-teens in 2009.

‘Wouldn’t your lot know? I mean the police have records of missing persons?’

‘We would, but it would help if we could narrow it down.’

Childs nodded. ‘OK, I can have a look, talk to my colleagues.’

‘Is there someone in the department who would have been around at the time?’

‘There’s Jocelyn Mitchell. She’s the head of department. Been here for donkey’s.’

‘OK, good. So, we’re looking for an adult female, possibly under forty, possibly linked to the hospital.’

‘As a member of staff or a patient?’

The question threw Anna.

Khosa answered, ‘Best to consider both.’

‘OK,’ said Childs. ‘I’ll speak to Jocelyn first.’

Anna glanced at her watch and gave him a card with her number on it. ‘Ring us if you find something, please.’

Childs nodded again and turned back to the barriers separating reception from the rest of the hospital, heading back towards the security checks.

‘This place gives me the creeps,’ Khosa said, looking up at the exposed metal ducting and white corrugated ceiling and the solid wall of glass and steel.

‘Then let’s get out of here, Ryia, before they find us both out and invite us in.’

Khosa gave Anna a ‘speak for yourself’ look, but she was smiling as she followed her out.