Cullen leaned forward on the sofa. "Can you describe your relationship with a Kimberly Milne."
"I told you on the phone last night." Wilson sighed. "We briefly worked together."
"You didn't mention you were in a relationship with Ms Milne for six years."
Wilson frowned. "Who told you this?"
"A friend of Ms Milne's," said Cullen.
"Sorry, the wounds are still a bit raw, you know? We only broke up last year."
"So I gather," said Cullen. "Was it Rob Thomson who moved in on your territory?"
"Aye, it was." Wilson looked out of the window, avoiding Cullen's gaze. He turned back, his eyes locking on. "What's this about? I've given you my source."
"I'm afraid we need a further source of corroboration," said Cullen, "now Ms Milne is deceased."
Wilson swallowed. "What?"
"She was found murdered at her flat last night," said Cullen.
There was a crash from another room. Wilson looked at the sitting room door.
"What was that?" said Cullen.
"Think it was outside," said Wilson.
The crash sounded again. Then a cry. "Scott!"
"Miller, keep an eye on him." Cullen left the room and went into the hall. "Hello?"
There was another noise from behind a door to the right, away from the flat entrance.
Cullen dashed for the door and tore it open. A bedroom. Alison lay tied up on the bed.
Alison
Tuesday 2nd August, 11.08pm
Alison stormed out of the stairwell onto Portobello High Street. She turned right and powered on towards the bus stop.
Scott Cullen is a total prick. He just used her like Katie had warned he would. He shagged her on Friday and couldn't get away quick enough. In hindsight, their date on Monday night had been a farce - he'd seemed distant and evasive. Then he'd rushed off again, some crap about a murder - like there were that many in bloody Edinburgh.
She walked past the five-a-side football pitches and realised she didn't know where she was going or how the hell she was getting home. The bus ticker wasn't showing one for another half an hour. She stopped just ahead of the traffic lights at King's Road and waited for a taxi to come along.
She couldn't reconcile the messages on Schoolbook to Scott's behaviour. They'd been so devotional - like she'd met Mr Right. In person and on the phone, Scott had seemed like such a prick. He'd been charm personified on Friday night, all those jokes about uniforms.
Two occupied taxis rolled past in quick succession.
She looked at the kerb and wanted the drain to swallow her up. Her anger was subsiding and she just wanted to be at home in bed with a glass of wine.
"You needing a lift?"
She looked up. A man in a silver car had pulled in, his window wound down. He was smiling, looked friendly.
"Where you going?"
He smiled. "Southside. Marchmont."
She thought about it for a split second - getting into a car with a stranger was stupidity, but she wanted to be home. She opened the passenger door and got in.
"Can you drop me at Grange Loan?"
*
*
*
Duncan Wilson stopped the car halfway round the park at Arthur's Seat.
"Why are you stopping?" asked Alison.
He punched her in the mouth, grabbed her by the hair. He pulled the tape out of the door pocket and covered her mouth. He swiftly bound her wrists together, taping her hands to the dashboard.
"Keep your mouth shut," he said.
She whimpered behind the tape. He punched her again, knocking her out. He panicked and hoped he hadn't killed her or seriously injured her. He needed her alive.
He wasn't as comfortable with this one - it wasn't part of his main objective. It was like Debi or Gail, maybe one seemingly random killing too many.
But that policeman... Scott Cullen. He'd met the arrogant bastard at Schoolbook, and spoken to him about those extracts he'd done for that idiot Kidd. When Cullen called just before eight, just after Duncan had killed Kim, he knew he had to act. He was getting too close, dangerously close to working out that it wasn't Rob that killed those women, dangerously close to working out that it was him.
He hacked into Cullen's Schoolbook account, like he'd done so many times that week since they'd met - like he'd done to so many of their accounts - and his course of action became clear. He'd been setting Alison up, Cullen's girlfriend. They hadn't been going out that long, so they weren't hand in pocket - there should be an opportunity to grab her. He used Cullen's mobile to track him down by GPS - watched him at Rob Thomson's flat, back at the station, in a pub, then at his flat.
Duncan had been outside Cullen's and saw Alison go in. He waited for an hour and saw Cullen arrive. He sprung into action not long after Alison left, watching her head along Portobello High Street. He'd diverted via the park by Arthur's Seat so that he didn't make a big breadcrumb trail home.
But now he was heading home with his bounty unconscious beside him. Maybe he'd take his time with her.
Cullen rushed forward. Alison had silver duct tape partially covering her mouth, like it was done in a hurry. He pulled the remaining tape off and started untying the rope.
"Scott, oh my God." She sucked in air.
Cullen held her. "It's going to be okay."
A scream came from the living room.
"Wait here." Cullen went back into the hall, just as a figure disappeared into the stairwell. He ran into the living room.
Miller lay on the floor, his white shirt slowly turning red. His eyes rolled, struggling to focus. "Fucking..." He clutched at his chest.
Cullen kneeled and pulled his mobile out. He struggled to control his fingers, as he called Bain and told him to get the fuck over there with an ambulance.
Miller tried to sit up. "Go get the fucker, Scotty, I'll be fine."
Cullen hesitated for a moment, then ran out of the flat. He looked down the stairwell. An old man was slowly climbing up, carrying a bag of shopping.
"Did anyone come down the stairs?" said Cullen.
"No, son."
"Call the police."
Cullen looked up - the ceiling hatch was open. Wilson was going to cut across the roof and descend another stairwell. Cullen didn't have time to work out which one, he'd have to go after him. If Cullen waited outside, Wilson could hide in any of the flats. He pulled himself up the ladder, hanging precariously over the centre of the stairwell, and climbed up onto the roof. He couldn't see Wilson.
The blow sent him sprawling.
Cullen tumbled and slid to the edge of the roof. He stopped himself just in time, his fingers clawing at the roof felt and eventually grabbing hold of the gutter pipe. His face hung over the edge, nothing between him and the car park below.
He pushed himself away, reaching round to feel the back of his head. It was wet. His hand was covered in blood.
Wilson was coming towards him, carrying a broken slate dripping with blood.
Cullen tried to pull himself to his feet, but his legs failed to respond.
"Thought you were pretty smart, didn't you?" said Wilson. "Finally caught up with me? Well, after I've finished with you, I'll go back and finish my work downstairs. Your friend down there can't have much time left. And as for your bird, well, I'll take my time with this one."
Cullen's feet slipped on the moss, preventing him from getting up.
Wilson was almost on him. "Should have brought my knife with me, but it's hanging out of your mate's guts. Had to buy a new one, can you believe it? This slate will do just fine."
"Why did you do it?" Cullen was desperately trying to buy time. His feet slipped again.
"Why does anyone do anything?" said Wilson. "Because they can. And because they can get away with it."
From this angle, Wilson seemed gigantic. Cullen could never beat him in an even fight.
"You won't get away with it. You'll have killed two police officers. They'll hunt you all over the world."
"Yeah?" Wilson smiled. "Oh well."
He raised the slate over his head, ready to bring it down on Cullen. He kicked out wildly, his left foot connecting to Wilson's knee with a satisfying crunch.
Wilson screamed, then staggered forward. He landed on Cullen. Wilson's fists started pounding into him - fire burned in his chest, head and arms. He couldn't breathe. He felt something snap in his chest. His whole body seared with pain.
Wilson straddled him and picked up the slate, ready to smash it down on Cullen's head.
Cullen brought his left knee up as hard as he could, sending a jolt of pain through his own body. It connected with something soft.
Cullen brought his knee up again. Wilson squealed and slumped forward, a dead weight. Cullen struggled to roll him off, his ears ringing from Wilson's yells. Ignoring the pain in his chest, he struggled to his feet.
Wilson rolled over and tried to get up. Cullen stumbled towards the ladder, sliding on the slippery roof.
Cullen heard Wilson behind him. He turned - Wilson had picked up the slate again. He staggered towards Cullen and swung the slate at his head. He lurched back, just avoiding the blow. He lost his footing and slid towards the edge of the roof again. He managed to stop himself and scrambled to his feet. He looked around. Wilson was limping towards him slowly, almost casually.
It had all come to this one moment. Wilson had killed four people. Miller lay dying, Cullen was next, then Alison.
Cullen edged up the slope. Wilson circled, holding the slate out in front of him like a knife. Cullen slid forward on the moss and kicked out. He connected solidly with Wilson's damaged knee. The knee buckled and Wilson pitched forward.
Cullen leapt onto Wilson and grabbed him in a half Nelson hold, arm locked tight behind his neck, his knee hard into the small of Wilson's back, immobilising him.
Cullen reached into his jacket pocket and pulled out his mobile. He called Bain with one hand, the other gripping Wilson tight.
"Where the fuck are you?"
"Not far away," said Bain. "Two minutes."
"I've got him on the roof." Cullen ended the call. "Duncan Wilson, I'm arresting you for the murder of Caroline Adamson. You are not obliged to say anything but anything you do say will be noted down and may be used in evidence. Do you understand?"
They were back at the station, standing outside the interview room with McNeill. DS Holdsworth, in his remit as First Aid officer, patched up Cullen's head. His ribs burned but he didn't want to go to hospital until he'd spoken to Wilson.
Keith Miller had been rushed off to the Royal infirmary - it was touch and go at best.
"I want to be in there," said Cullen.
"Sundance, you're in no fit state to be interviewing anyone."
"I don't care," said Cullen. "I need to hear his words. I'll sit at the back."
Bain raised his arms in the air. "Come on, then."
Cullen smiled. "Thank you. How's Alison?"
"Your bird?" said Bain. "She'll pull through."
A frown passed over McNeill's face.
"Did they find anything in his flat?" said Cullen. "Any evidence? There are two missing laptops."
Bain shared a long look with McNeill then slowly nodded. "Aye, we found something. Not the laptops, though."
"What then?"
"We
think
we've found Caroline's flat keys," said Bain. "Irvine's around there now, checking they fit the locks."
Cullen breathed a sigh of relief. "Aren't you going to say anything?"
"Eh?"
"Aren't you going to apologise to me?" said Cullen.
Bain put his hands on his hips. "Don't fuckin' push it, Sundance. I'll say you did some good work there. I do need to give you a doing about something, though."
Cullen sighed. "What?"
"Doing more unauthorised phone checks," said Bain.
"Gail's number, right?"
"Right."
"Did anything come back?" said Cullen.
"A fuckin' huge bill." Bain gave a deep breath. "Tommy traced it to a phone from the same consignment as that one for Caroline."
"You're kidding me."
"No, it was in the next transaction at that till," said Bain. "You fuckin' missed that one. Our killer bought two phones in separate transactions."
Cullen ran his hand through his hair. His head throbbed when he touched the bandage. "So that links the killer to Gail and Caroline."
"Got it in one," said Bain.
"And Rob Thomson?"
"I've let him go." Bain laughed bitterly. He thumbed towards the interview room. "We may have to use him as a witness against this chump."
"Just hope he doesn't sue," said Cullen.
"Aye." Bain rubbed his moustache. "The reason I was on the phone to Tommy Smith was to get a trace on that 999 call."
"And?"
"Untraceable," said Bain. "He did ask me where I wanted the bill sent, which pissed me right off, so I got him talking."
"Well, some good came of it," said Cullen.
"Aye, I suppose," said Bain. "Right, let's get in there and interview him."
Bain and McNeill were leading the interview. Cullen sat at the back of the room behind Bain, with PC Buxton by the door.
"I will refer you to the point about police brutality, Inspector Bain." McLintock wore a more sober outfit than when he'd defended Rob Thomson. "Your officer gave chase to my client and then assaulted him."
"And I'll remind
you
that your client had just stuck a knife in another of my officers," said Bain. "The incident you're referring to was actually your client clattering an officer on the head with a slate as the officer popped his head out of a roof hatch."
"Inspector, my client has suffered a severe injury to his knee and his shoulder as a result of the attentions of one of your men," said McLintock.
"Your client had the victim of a kidnapping in his bedroom with the probable intention of murdering her," said Bain. "And that's in addition to the four murders we intend charging him with. So let's cut out all of this rubbish, shall we?"