Cullen didn't say anything, deliberately restraining himself from reminding Bain it was he who linked Gail McBride to the other murders just that morning.
Bain squared up to him. "You're fuckin' about here, Constable. Every single task you've been set you've not completed. I've found you away with other officers on random trips at least three times today and I still don't have corroboration of the death threats."
Cullen stepped back. He couldn't even look at Bain for fear of punching him.
Bain pointed at Cullen. "I need you to go back to your desk, pick up the phone, dial some numbers, speak to some people and verify those fuckin' death threats."
Cullen took a deep breath and tried to work out whether to punch or head butt.
"Now, Cullen," said Bain. "Those are the witnesses I want at the trial. I'm away to speak to the Procurator Fiscal, see if I can pull Thomson back in." He took a step back, shaking his head. "Verify those death threats."
Cullen turned the key in the ignition, his pulse still racing from the confrontation, his hands still shaking.
There was a rap on the passenger side window. McNeill.
Cullen took a deep breath and turned the engine off. He reached over and opened the door to let her in.
"Are you on your way home?" said McNeill.
Cullen nodded and looked away. "I just can't take any more of this nonsense from him."
"It was uncalled for," said McNeill. "I don't know what the hell he's playing at."
"I know exactly what he's playing at," said Cullen. "It's like you've been saying, they're all playing for Turnbull's job. If Bain can get a quick conviction here then he's a shoo-in for it."
"It's that or the pressure of this case," said McNeill. "His swearing is getting worse. I wouldn't be at all surprised if Strathclyde murder squad pitches up here soon because we've made such a mess of it."
They sat in silence for a while. Cullen's pulse gradually slowed. "Am I out of order here? I seem to be the only one challenging him."
"I am as well," said McNeill.
"Are you?" said Cullen. "It feels like it's just me. Bain's giving me a total kicking for it."
"That's just Bain being Bain."
"Yeah, well, if it wasn't just me shouting about it," said Cullen, "he'd maybe listen to some sense. I need you to back me up."
McNeill glared at him. "Scott, you're lashing out."
"I'm not," said Cullen. "I'm in at the deep end here."
McNeill closed her eyes and took a deep breath. "Do you have an alternative suspect?"
Cullen thought it through for a few seconds and realised he didn't. "Do I have to? Bain's going after Rob Thomson with very little evidence."
"He's under pressure to get someone," said McNeill. "I'm not defending his behaviour but unless we've got a credible alternative, Bain won't listen to you."
Cullen looked out of the driver's window across the car park, past the rows of cars, to the ramp up to street level at the end. He thought about what she said - much as he hated to admit it, he really didn't have an alternative. She was right.
"Are you still going home?" said McNeill.
"I'm not exactly doing much good here, am I?" said Cullen. "And I'm certainly getting no thanks for it."
"Just because Bain doesn't appreciate your efforts, doesn't mean you're not helping," said McNeill. "You're probably the only one finding leads."
"Thanks."
"Why do you think it's not Rob Thomson?"
Cullen drummed his fingers on the steering wheel. "I don't know whether he did it or not, but I do know we don't have any solid evidence against him. Everything we have is just circumstantial, hypothetical supposition. Bain needs a collar and Thomson looks like he fits the bill. That CCTV footage is the clincher for me. It's totally inconclusive. All he can say definitively is it's a big man in a hoodie. And those death threats are just hearsay as far as I can tell. We've got nobody backing it up. No corroboration at all."
"Has anyone denied them, though?" said McNeill.
Cullen frowned. "Just Rob Thomson, I suppose."
"And who else have you tried?" said McNeill.
"Caroline's friends on Schoolbook." Cullen thought it through - Caldwell had contacted more people than he had, but neither of them had found anyone who'd heard of the threats. He punched the steering wheel. "I've been a total idiot."
"Eh?"
"You've just given me a good idea."
Cullen knocked on the door. After a few seconds, it was answered.
Amy Cousens looked awful, her eyes circled with dark rings. This was the first time Cullen had seen her since Caroline's body was found. "What do you want?"
"I need to speak to you about a couple of things," said Cullen.
"Come in, then," said Amy, somewhat reluctantly.
Cullen followed her inside. Jack was sitting playing with his Doctor Who dolls, though he appeared quieter than before. He was surprised the boy was still there. He wondered if Jack knew what had happened to his mother.
Amy collapsed into the armchair. "I take it there's been nothing?"
Cullen grimaced. "Not yet, I'm afraid."
"Jesus." Amy had a hanky in her hand and she clenched it tighter. "I hope they catch him."
"How are you doing?" said Cullen.
Amy sniffed back a tear. "It's hard. I'm not coping too well. I can't believe she's dead. Looking after Jack is keeping my mind off it."
It was the opposite reaction to that of Caroline's parents the other day - no stoic Calvinist 'get on with it', just a tidal wave of emotion. He gestured towards Jack. "How's he doing?"
"Not great," said Amy. "He keeps asking where his mummy is. Caz's dad came through this morning. He's clearing out her flat. He's taking Jack back to Carnoustie this evening."
"How's Rob taking that?"
Amy sighed. "From what I hear he's fine with it. So long as he can see him every so often, he said he doesn't mind. Besides, he's got a few things on his plate."
Cullen noted it down.
"Why are you here?" said Amy. "I don't need you to babysit me, you know?"
"I'm not attempting to," said Cullen. "Did Caroline ever say anything about Rob making death threats against her?"
Amy sat forward in the chair, like she'd been jolted. "
Death threats
?"
"Yes," said Cullen. "After they divorced. Someone who knew Caroline told us it was common knowledge in Carnoustie."
Amy shrugged. "Caroline didn't have much to do with that place after she left university. Obviously she still saw her parents, but she didn't go back to see her pals or anything. I'm not surprised there were rumours like that going round, though."
"Not surprised?"
"Well, you must know what small towns are like," said Amy. "People make shite up and, before you know, it's spread all around the place."
"Do you know if Rob kept in touch with people there?" said Cullen.
"Don't think so."
"Okay." Cullen figured the rumours had to come from Caroline's friends if there was any truth to them - Thomson wasn't likely to go around bragging about them. "Can you give me a little bit more about the sort of relationship Caroline and Rob had after the divorce?"
Amy stared at the coffee table. "From what I remember, Rob really backed off, just let the divorce go through. I don't think he even saw Jack till the divorce papers were signed."
"How long would that have been?" said Cullen.
"Couple of months."
"And after the divorce, how often did he see him?"
"Afterwards, it was just Rob picking Jack up for his paternal visits," said Amy. "And not every time he was supposed to, either. Rob and Caroline didn't speak about anything other than Rob's access."
"You mention he wasn't reliable," said Cullen. "Did Caroline give him a hard time about it? Did she make anything of it?"
"Hardly," said Amy. "She figured they were better off without him in their lives. She didn't push it. She'd bitch to me about it, but it was more about having to change her plans last minute when he didn't show up."
"And you never heard of any death threats?"
"No way," said Amy. "Caroline would've told me."
Cullen talked as he walked onto Leith Walk, clutching his mobile to his ear.
"Mr Allen, it's DC Cullen again. We spoke on Friday about Caroline Adamson."
"I remember." Steve Allen sounded torn up about her death.
"Are you okay?" said Cullen.
"No, I'm not doing too good. I suppose I'll cope. Eventually. Have you got anywhere?"
"We're making good progress," said Cullen. "I wanted to ask you some more questions, if that's okay?"
"Fine," said Allen.
"Okay," said Cullen. "You'd been friends with Caroline from your Carnoustie days, that's correct, isn't it?"
"It is."
"We recently received some information from an acquaintance of Caroline's that Rob Thomson had made death threats to her after their divorce," said Cullen. "I wondered if you'd heard the same story."
"Who told you that?"
"I'm not at liberty to divulge that," said Cullen.
Allen exhaled down the line. "I was one of Caroline's closest friends. She never told me anything like that and, believe me, she would have. We shared things with each other that we wouldn't with other people and neither of us would blab, certainly not to anyone from Carnoustie." He almost spat out the name of the town.
"So just to confirm, you've never heard anything about death threats?" said Cullen.
"That's correct."
"Thank you for your time," said Cullen. "I'll be in touch if I need to."
He ended the call. He was outside Caroline's flat. He pressed the buzzer.
*
*
*
David Adamson clutched the cup of tea in his hand. "So you've heard we're taking the boy up to Carnoustie today?"
Cullen nodded as he put his empty mug on the window sill of Caroline's living room. Most of the furniture had gone, the flat an empty shell. The room was piled high with boxes and bin bags, most of her possessions now stowed away.
"It's for the best," said Adamson. "He's a lovely wee laddie. He doesn't deserve what's happened to him. None of us do." He took another sip of tea. "Are you any closer to finding this animal?"
"I can assure you we're doing all we can," said Cullen. "We're still progressing a few leads. We're confident we'll find whoever killed your daughter."
"I hear he did this to other girls," said Adamson. "Is that right?"
Cullen nodded slowly. "There have been some other murders in the city over the last couple of days and we're investigating any links, as we are with any murders over the last few years."
Adamson gripped the cup in his hand. "Why haven't you got him yet?"
"There's nothing I can confirm yet, Mr Adamson, but I can assure you this case has the highest priority in Lothian & Borders just now."
Adamson put his cup onto the coffee table.
"We received a report your son-in-law made some death threats against Caroline," said Cullen.
Adamson frowned at him.
"I take it you weren't aware of this?"
"No," said Adamson. "No, I wasn't."
"Is it likely you wouldn't have heard?"
Adamson paused for a few seconds. "My daughter could be very headstrong. She didn't want to share much with either myself or my wife."
His eyes welled up - Cullen thought about how his own parents didn't know much about his private life either.
Adamson cleared his throat. "No, I'm sure there was nothing like that, understand? I know his father very well and I still play golf with him. We were both very disappointed with what happened between Caroline and Rob, you know? But it happened."
"How would you describe their relationship after the divorce?" said Cullen.
"After the divorce?" Adamson took a deep breath then sat forward on the sofa, leaning in towards Cullen. "I don't know. Things seemed to improve between them. It was fairly amicable. And believe you me, if I'd had wind of anything like these threats, I would've battered him, regardless of how big he is."
Half an hour later, Cullen sat in the station canteen at a table in the corner, keeping away from everyone. In truth, he was hiding from another confrontation with Bain. The information he'd just gained was bound to kick off another fight, especially if Bain was trying to get the PF to charge Rob Thomson.
He took the final bite of his chicken salad sandwich and crumpled the bag into a ball, before drinking the last of the Dr Pepper.
It was after half six in the evening and he was messing about with his iPhone, checking the Aberdeen football news on the BBC. There were rumours they were signing some guy who had played for Hearts a few years previously. He didn't have great expectations for the coming season. When Craig Brown became Aberdeen manager, Cullen's flatmate Tom reckoned he would make them hard to beat - in Cullen's eyes, all he'd done was make them unable to win.
A notification pinged up from the Schoolbook app - another message from Alison.
"Looking forward to meeting tonight. See you at eight."
He couldn't remember arranging to meet her. It must have been something he said the previous evening as he rushed off.
His reply read
"Not likely to get away tonight. Will call."
He had no intention of calling.
He sighed then ran a search for Martin Webb again, to see if anything had changed with the account. Schoolbook hadn't removed the profile yet, the same chiselled model face beaming out of the page.
After a moment's hesitation, he tapped on the button to add Martin Webb as a friend.
He immediately regretted it. He put his phone down, feeling like an idiot. That's something I can't undo, he thought.
The phone pinged again. He picked it up - another message from Alison -
"I understand, but you need to make some time for me."
He had no idea what she thought their relationship status was, but it wasn't what it said on her Schoolbook page.
Another message pinged up on the screen - he and Martin Webb were now friends. He sat and stared at the handset for a few minutes, thinking it through. The account was not only active but Martin Webb was still using it. Cullen wondered if it was automatic or a manual action on the part of whoever was behind the account. Rob Thomson wasn't in police custody at the moment, so it played right into Bain's vendetta.