Sam reluctantly stayed at the District under the watch of Platt. He finally smiled at her when, while Adam was still in earshot she turned to Sam. "Did Adam ever tell you about the time he was chasing a guy and slipped and ended face first in a puddle?"

"No."

"Looked like a drowned rat and whined about it for days."

The rest of the team were waiting upstairs and had a photo of Robert Berendorf up on the whiteboard with his LKA and a brief history. He was a clean sheet as far as they could tell apart from a couple of parking tickets and a speeding fine from five years ago.

Kim and Adam didn't even take off their jackets, they weren't planning on being here long. "What's his deal?"

"Not married but has two kids, nine and six that his ex has custody of but judging by his social media he often had plenty of photos of them out and about doing things. He's a Plumber. Has Kate had any plumbing work done or issues?"

"No idea. There were no receipts in the pile. What about her bank accounts any transfers? Venmo? Cash app?"

Torres pulled up Kate's bank accounts. It felt uncomfortable to be trawling through Ruzek's sisters private life while Ruzek peered over his shoulder. There was one payment to Berendorf Plumbing three months ago. "There." Adam spotted it first. "That's a link."

"What are you going to do?" Voight asked.

"Just a knock and talk Boss."

"Make sure that's all it is. For all we know it is completely above board. Actually it's most like that it is, but in lieu of no other leads check it out. Kev, you go with." He nodded to Kevin. "Let him do the talking."

Kevin grabbed his jacket and reminded them both that they were on a very short leash and if anything went sideways it was on Kevin's shoulders.

Robert Berendorf was very unhelpful. "Who?"

Adam showed him a photo of Kate. "Take a look."

"Don't know her, sorry." He shrugged and tried to close the door but Kevin held out his hand to stop him. It was a strange attitude to have to a simple question.

"Take another look." Kevin nodded at the phone. They had parked up the road a little way and surveyed the house first. It was neat enough, not flash and the plumbing van was parked outside. The street was middle class and could be any suburban neighbourhood. Nothing jumped out at them although they both noted a few twitching curtains as they cased the house and made a note to get someone to come talk to the neighbors.

"Look I see a lot of customers. I don't recognise her."

"Why is she calling you… " Adam looked at his phone. "…eight times in the past three weeks?"

"Plumbing issue I guess."

"You do free plumbing?"

"No."

"So she owes you a lot then? 8 call outs and not one single payment?"

Robert shifted a little uncomfortably from foot to foot. "What exactly is this about?"

"We are trying to find her, you've had contact with her." Adam added bluntly.

"No." Robert snapped back. "She called me constantly. I never answered. I wasn't interested."

"Interested in what?" The longer they kept him talking the more he was spilling.

"Whatever it was that she wanted. It was a mistake okay. I lost my mind for a bit, we hooked up once and that was it. She was freaking me out. I've got a girlfriend okay, she doesn't need to know about this. I wanted nothing to do with her." Robert was getting annoyed and full of attitude. "She was obsessed. Crazy ass chick."

Kevin stepped in front of Adam as he could sense he was about to do something stupid. This was exactly what Voight had warned him about.

"When was the last time she called you?" Kevin took over. "It's important we find her, she has a young son who is worried about her." He tried to defuse the situation a little as both Robert and Adam were steaming and it was like a tinder box.

"Don't know." He folded his arms across his chest.

"How about you go grab your phone and check." Adam muttered.

"I don't have to."

"Well, either you can check your phone now or we take you with us and get a Judge to issue a warrant for your phone. It's a pretty simple choice."

"I guess I will wait for the warrant then."

It was a tense ride back to the District with Robert handcuffed in the back seat. He'd done himself no favors by abusing both Kevin and Adam for harassing him and had pushed them both when they tried to stop him closing the front door causing Adam to stumble backwards down the step and twist his ankle slightly. He was in no mood for any of this.

Hobbling up the stairs with Robert Kim was up out of her chair as soon as she saw him. "What happened?"

Adam passed Robert off the Kevin and he took him through to the interview room. "Idiot got a little pushy and I twisted my ankle. It's fine." He squeezed her arm quickly. "Hey, I need you to a deep dive on this guy. Admitted that he hooked up with Kate once, a couple of months ago and she's been harassing him ever since. Also has a girlfriend but won't give a name, see what you can find huh." He scratched his beard quickly. "Oh and get patrol to do a knock on the neighbors and see if anyone has seen Kate."

Kim nodded towards to break room. "Sam's in there. I think he'd like to see you."

"Does he remember something?"

"No, he's just been asking when you'll be back." Kim lowered her voice and pushed him gently away from her desk so she could start working. "He's just … you know, like Mack gets when one of us is out late and she doesn't know what's going on." They didn't like to talk about Mack's anxiety too publicly.

He pushed open the breakroom door and Sam briefly looked up from his iPad. "Hey Bud. Whatcha playing?"

"Nothing." He shrugged. "Did you find Mom?"

Adam sat down beside him and put his feet up on the chair. "Not yet, getting closer though." Sam didn't even look up from the screen. "Hey, do you remember Mom having to call a plumber? Broken pipes, leaking taps, toilet broken?"

"Yeah. One of the taps broke. She was going to call you but you were busy. Some guy came and fixed it."

"Did you see him?"

"Yeah."

Adam showed him a photo of Robert and his plumbing van and Sam confirmed that he was the guy. "Did you only see him once?"

"Nah, he came back a couple of times."

"To fix stuff?"

"He came for dinner once."

Adam reached for the iPad and closed the screen cover. "Sam, just for a minute." Adam responded to Sam's glare. "Tell me about this plumber? When did he come for dinner, where they okay? Did they argue? Did he stay the night?"

"I don't know. I went to bed."

"Was he there in the morning?"

"No." Sam sighed. He was clearly over people talking to him. "Can I play my game now?"

Adam pinched the bridge of his nose. "Sam, buddy. This is important. This might help find your mom. Isn't this what you want me to do?" He spoke a little harsher than he should've. He had an overwhelming sense of dread come over him and it was hard to control it but he had to rein it in in front of Sam. "Look, I'll just be out there." He pointed to the bullpen. "If you remember anything let me know hey?"

It had been decided that Adam wouldn't talk to Robert. It was left up to Kevin and Kim. It was frustrating as hell but Voight kept shortening his leash the longer this went on. He couldn't blame him, he didn't have the best track record of staying well out of things when he needed to.

He was watching and pacing in the observation room as Robert continued to deny having more than 'a hook up' with Kate until Voight sent him packing because he was getting agitated. "Go check the Bolo's." he barked at him.

Adam wasn't the only one getting anxious about this case. Nothing so far pointed to a happy ending, so not only did he worry about that, about some innocent single mother's disappearance but there was also the effect it would have on half his team. It was too close to the bone and potentially too much for them after a few years of some brutal trauma. They'd lost a baby, had their daughter kidnapped and both been shot and left for dead and finally they were in clear waters and he wanted it to stay that way.

Adam leant back in his chair and clasped his hands behind his head and closed his eyes trying to clear his mind. Thinking clearly was becoming increasingly difficult. This was his job and not being able to find his sister was festering inside him. They should be closer than they were. Opening his eyes he glanced at the break room door and contemplated trying to talk to Sam again but he'd shut down. Perhaps getting him home might help, he seemed more relaxed and open in the safety of a familiar place.

He couldn't stop his mind wandering to what might happen if the worst outcome was realised.

They had to let Robert go, he'd done nothing but hook up with Kate and there was nothing illegal about that but they were going to keep an eye on him anyway. Even the messages sent weren't overly remarkable, there were no threats or demands. Covert surveillance was organised and Voight had to pull some strings for that because their case was flimsy.

The Patrol door knock yielded nothing, nobody had seen a woman at his house, Kate's car and only had glowing reports about Robert, always happy to fix their plumbing for them, kept to himself, quiet, had his kids on weekends occasionally.

"He's in it up to his eyeballs." Adam argued, wildly flinging his arms in the direction of the interrogation room. "You know he is?"

"We don't know that, Adam…" Voight stood fast. "… we don't have the evidence. You know we don't, I take this to a Judge and we'd be laughed out of the building. So we key an eye on him and do the work."

"And Kate could be dead." The last time his voice shook like it did was when Kim was missing. "I mean… she could be hurt, she's got a son."

"Adam." Kim stepped forward and placed one hand on his arm and waited until he looked at her. The agony in his eyes took the air from her lungs. "We keep going okay?" she nodded. "Okay?"

Adam nodded eventually and exhaled. "So what now?"

"We keep an eye on Robert, we dig into his girlfriend, we keep digging into their social media, we check our bolos and you take Sam home."

"Boss, I can help."

"I know, but Sam doesn't need to be here. It's best if he's not. Unless you have somewhere else he can go you need to handle it."

Reluctantly he took Sam home, picking up Makayla and some take out on the way home and while Mack was happy to see her cousin Sam was subdued. Adam tried to get her to give him some space but that was impossible, she was desperate to cheer him up.

Kim called just after dinner to check in and say goodnight to Makayla. They were still working and hadn't uncovered anything useful yet. He had complete faith in Kim finding the missing piece, she always did.

He just wasn't good at waiting.

As soon as they were both in bed and asleep he pulled out his laptop and started working. He worked out Kate's Facebook password and started going through all her posts, contacts and friends. Making note of anyone who had liked or commented on posts recently but she wasn't a prolific poster and it all seemed so banal.

His laptop was still on his lap when Kim got home, although he was sound asleep.

She quietly grabbed the laptop and closed the lid, sitting down beside him she reached for his hand. "Adam honey." She whispered.

"What? What is it?" It was the tone of her voice and the look on her face that he picked up on as soon as he focused.

"They found Kate's car. Kevin is outside waiting for you."

"And?"

Kim exhaled slowly. It hurt to say. "Burnt out, there is a body inside."