Shae’s heart tapped an excited rhythm against her breastbone as she followed Capelli down the hallway outside of the intelligence office twenty minutes later. Bridges had given her the green light to survey the scene of Friday’s fire with Capelli, although he’d texted her the instant he’d gotten off the phone with Sinclair to remind her in no uncertain terms that she’d better keep her nose spic and span while she did. In her defense, she hadn’t gone looking to break the rules when she’d popped open that file on the restaurant fire—in fact, she’d been trying to suck it up and do the exact opposite so she could grit her way through Bridges’s punishment and get her ass back to the action of Station Seventeen, where it belonged. But working with the intelligence unit to catch some lowlife who had committed both murder and arson?

That was so much better than sitting in some stuffy office filing even stuffier paperwork. So she’d impulsively fractured a few little rules by borrowing the file. Was it really that big a deal if it ended up getting intelligence the lead they needed?

She could help. If her experience as a firefighter could help Sinclair’s team figure out who was setting these fires and why, she could potentially save lives.

And hell if that wasn’t the biggest reason of all to jump right in.

“Okay!” Shae said, smacking her hands together and rubbing them with borderline glee. “What do we do first?”

Capelli frowned slightly before descending the stairs leading to the Thirty-Third’s first floor and bustling main hub. “We make a plan, obviously.”

“So we’re not going to go out there and see what strikes us as odd, then investigate from there?” A step-by-step plan seemed a little rigid, and by “a little”, she really meant “a shitload”. Then again, this was her super-serious, super-sexy partner in crime they were talking about. Shae probably shouldn’t be shocked that he wanted to go by the book. Hell, with all that smoldering determination lurking in his stare, he’d probably written the book.

She cleared her throat and kicked aside the hard tingle running from her spine to her more delicate parts at the errant reminder of Capelli’s sexiness. She was here for the case now, and anyway, he’d made it wickedly clear the other night that he’d only been interested when he’d thought she was someone else.

Capelli looked at her over one broad shoulder as they cleared the bottom of the stairs and began navigating their way through the bustling lobby of the Thirty-Third. “We’ll be far more efficient with a specific strategy in place, especially since there’s no report from the fire marshal for us to use as a baseline yet. The crime lab already went through the scene to collect whatever evidence they could for the murder.”

“So now we just have to go through and figure out the fire, then see where it fits with your dead body.”

“It’s not as easy as it sounds,” he said, pushing open the main door to the precinct. Rather than going through, though, he shifted back so she could go first, and ooookay, so much for that tingle between her legs taking a hike.

“Thank you.” Shae slipped past him, their boots falling into step together a few seconds later as they descended the stairs leading to the tidy sidewalk in front of the stone and brick building. “And for the record, I don’t think this is going to be easy. But I definitely think it’s going to be fun.”

Capelli exhaled, his breath puffing around his face before scattering in the chilly afternoon air. “I’m pretty sure that word doesn’t mean what you think it means.”

But Shae just grinned. “Oh, it does. I just have a very wide net when it comes to adventure.”

“You don’t have to remind me,” he said. Ah, she’d kind of earned that one, what with the whole showing up unexpectedly/illicitly borrowed arson file thing.

“I know I might not go about things in a very orderly way, which probably drives you bat shit insane,” Shae said, slowing to a stop next to the dark blue unmarked car where Capelli had just done the same. “But I’m not making light of this. I really do want to help. We’re both on the same side here.”

She braced herself for a response that held more of the same high-logic, low-tolerance-for-anything-not-in-black-and-white attitude he’d dished out ever since he’d questioned her at the scene of the meth lab fire.

So her jaw damn near dropped to the pavement when he said, “You know what, you’re right.”

“I’m sorry, what?”

Capelli pulled a key fob from the pocket of his black canvas jacket and pressed a button, the locks on the unmarked car popping open with a heavy click-click. “I said, you’re right. As impulsive as I think your methods are, you wouldn’t have come here if you didn’t want to help. Intelligence has two dead bodies and exactly zero leads, and at this point, you and I working together does give us the best statistical chance of making any headway on the case.”

“Aw,” Shae said, unable to keep her tart laughter in check. “You sweet talker. I bet you say that to all the girls.”

“Actually, I don’t.” He paused, dropping his hand halfway to the passenger door handle and turning to step toward her instead. “But I’ll do whatever it takes to solve this murder.”

A sudden flash of hot intensity moved through his stare, cutting through the methodical calm she was so accustomed to, and for a second, her breath froze to a stop in her lungs. “Oh,” she finally managed, although the word sounded oddly soft as it escaped. “Okay then. Partners?”

Shae stuck out her hand, the exhilaration in her chest resurfacing quickly at the slight hint of a smile on Capelli’s face as he wrapped his fingers around hers for a firm shake. “Partners with rules,” he qualified.

“Excellent!” She didn’t even bother dialing back her grin. Not that she ever bothered to dial back anything else either, but… “This is going to be so much fun. Come on—I’ll be Starsky, you be Hutch.”

Huh. Looked like that tiny smile of his had a very short shelf life. “That’s not really how any of this works,” he said, leaning in to open the passenger side door so she could slide into the car.

“Okay, fine,” she said after he’d slammed her door and moved around to let himself into the driver’s side. “I’ll be Hutch. So how do you want to work the plan?”

Capelli traded his darkly framed glasses for a pair of Ray-Ban aviators, but not before giving her a look that seemed to question her sanity. “The way I always do. We’ll examine the scene, consider all the variables, then weigh possible scenarios based on our findings.”

Shae’s brows went up. “You make it sound so serious.”

“That’s because it is,” Capelli said, matter-of-fact.

“I know.” She thought of the body she’d recovered at the meth lab fire, instantly sobering. “I guess I just meant that your plan is really technical. Don’t you ever go with your gut?”

He navigated traffic, which was thankfully light. “I can’t quantify my gut, so no.”

“So you never trust something on pure faith?” she asked, surprise knocking through her veins at the concept.

“No.”

“Never ever?”

“No.”

Whether it was the utter conviction of his tone or the sudden tension radiating from his body, she couldn’t be sure. But something about Capelli’s reply kept her from pushing back.

“Okay then. If you think we should go with the facts, I’m game to start there.”

They settled into silence for a few minutes, and oddly, it wasn’t stiff or uncomfortable. Shae watched the buildings go by in flashes of brick and sunlight and glass, but wait. Something about the path Capelli was on wasn’t right.

“Aren’t we heading to North Point?” she asked, pointing out the window to the turn he totally should have taken but had bypassed without pause.

“Mmm hmm. But first we’re swinging by the arson investigation office so you can return that file.”

God, he was so rules-oriented that she was almost tempted to laugh. “But what if we need it?”

“We won’t need it.”

Capelli didn’t elaborate, but come on. Facts were his jam. He couldn’t really mean that. “We might need it,” Shae argued, but he shook his head, resolute.

“You took it without permission, McCullough, and rules are rules. The file needs to go back.” He paused for a second, then continued as if he’d anticipated her argument. “We need to look at the fire at this murder scene independently of the one at the restaurant anyway. Comparing them right off the bat might tempt us to stretch, and the last thing we need is to jump to conclusions that aren’t there. Analyze first, then hypothesize.”

Shae opened her mouth. Then closed it with an internal curse. Dammit, his process did sort of make sense. Even if it was uber rigid.

“Okay, okay. I’ll put the file back before we go.”

A few more minutes had them at the arson investigation office, and a few more after that had the file safe and sound on her temporary desk in Natalie’s office. Captain Bridges must have let Frank and Natalie know she wouldn’t be back for the rest of the day, because neither one of them batted so much as a lash at her parting “see you tomorrow”, even though it was barely one o’clock.

Shae settled back into the passenger seat of the unmarked police car, and as tempted as she was to argue that maybe they should loosen their plan of action to include some action (God, she was so. So. Tempted), she didn’t. Capelli made his way through downtown, crossing over to the dingier and less reputable streets of North Point, and Shae gestured out the windshield at the intersection they were quickly approaching.

“I know your GPS probably says to keep going on Hamilton, but if you turn here on Queen Anne and use the side street as a cut-through, you’ll save a little time.”

“If that was faster, the GPS would say so,” he pointed out, but Shae just shrugged.

“Sure. And if the GPS knew that the light at Hamilton and Glendale takes conservatively a month to turn green, and that the intersection is the third most dangerous in all of Remington, it would tell you to take Queen Anne.”

Capelli slowed for the four-way stop sign at Hamilton and Queen Anne, using the opportunity to look more carefully at the digital map on the dashboard screen before engaging the turn signal and taking her advice. They looped back through to Hamilton and Glendale, where—ha!—a huge line of cars sat waiting for the light on the other side.

His brows traveled toward his neatly combed hairline, and he surprised her with a deferent nod. “Thanks.”

“You tried it just to prove me wrong, didn’t you?” She capped the question with enough of a smile to remove any heat it might’ve carried. After all, she tested boundaries on a daily basis. Far be it for her to get pissy over someone else returning the favor.

“I tried it to test the theory,” Capelli said, lifting one hand from the steering wheel in concession a second later as he added, “But in fairness, no. I didn’t think going that way would be faster.”

“See? Sometimes I use my powers for good,” she teased. “And sometimes, the most logical way isn’t the best path between two points.”

The downward twitch of his lips was a direct translation of let’s not get crazy, but he didn’t voice it. “Do you know South Hill that well, too?” he ventured instead, and oh, what the hell. She indulged him.

“Pretty much. The south side of Remington is easier to navigate though. Well, except for the construction cluster fuck going on over where the mayor is building his new McMansion,” Shae added. The thing was actually more monstrosity than mansion, but then again, Mayor Bradley Aldrich III was all about flash and dazzle. The stupid thing had turrets. Plural. Who even did that in this day and age, seriously?

“You must go on a lot of calls in this area to be so familiar with the traffic patterns,” Capelli said. The observation brought her back to the here-and-now of the moment, and she nodded, giving the area around them a good scan through her window.

“We do. Seventeen is right between North Point and South Hill, but we tend to come down here more often. Usually the calls are pretty small time—medical assists and small fires. Stuff like that. I’ve responded to enough car wrecks at that intersection to tell you the stats on that one are definitely legit, though.”

“So some of the calls you go on aren’t quite so small time, then.”

Capelli’s voice lifted in curiosity—just slightly, but it was enough—and Shae met it with a nod.

“Well, yeah. Obviously, this one we’re going to check out was pretty bad. And there was that fire three months ago that ended up being related to the DuPree case.” Her brain skimmed the place where she’d compartmentalized the double homicide that sociopath had committed, then tried to cover up with a nasty fire, and her heart began to pound. Breathe in. Breathe out. Breathe in…

“I remember it,” Capelli said. He stayed quiet for a few passing blocks, but the hard set of his jawline told Shae his thoughts were far from idle. He didn’t say anything, though, and by the time they’d crossed over to Crestridge Drive and came to a stop in front of the scene of Friday’s meth lab fire, her heart began pounding for a whole new set of reasons.

“Wow,” Shae said, taking in the window-scorched and worse-for-wear house in front of them. “This place is definitely a loss.”

“That may have been the point,” Capelli reminded her. “We won’t really know until we go in and take a closer look.”

She thought about the challenge in front of them, adrenaline and excitement swirling low in her belly. “And here I thought you’d never ask.”

Getting out of the car, Shae scanned their surroundings in more detail as they walked a path over the crumbling sidewalk. The tang of stale smoke still hung low in the air, sliding through her senses with her first full breath. The bright blue sky was an odd backdrop for the dingy, fire-eaten house, which—whoa—bore dark, angry scorch marks around all but one of the windows and fresh sheets of plywood nailed over three of the ground-level spaces where the glass had stood.

“Further proof that the Halligan bar is eight and a half pounds of ‘fuck shit up’,” she murmured under her breath.

“I’m sorry?” Capelli’s brows breached the top rim of his sunglasses, and Shae gestured to the boarded-up windows.

“It’s standard operating procedure for us to break the windows and use the hoses from the exterior when a fire’s running too hot to fight from the inside. I’d kind of forgotten how bad the damage looks a few days later, though.”

She eyeballed the house again as they continued their approach on the walkway. Yellow tape stamped with the warning No Trespassing by Order of the Remington Police Department had been threaded across a six-foot swath of the part of the chain link fence where the gate was centered, and she didn’t hesitate to slide a palm beneath it to swing the waist-high door on its hinges.

“Come on, let’s get a closer look.”

“We’ll have to be careful,” Capelli said with a pointed glance and a truckload of implication.

But Shae didn’t even break stride on the front walkway. “Not to put too fine a point on it, but I ran into this place when it was burning down. I’m pretty sure I can handle a walk-through now that the fire’s out.”

“I didn’t say you couldn’t handle it,” he replied, and funny, his tone backed the words right up. “I said we’ll have to be careful. If we go too fast, we might miss something important.”

Shae’s feet tempted her to hitch in surprise, but dammit, he did have a point. “Okay,” she said, forcing her steps to slow despite the squall of protest from her adrenal gland. They made their way up the rest of the front walk, then past the posted notices from both the police department and the fire marshal taped across the front door. Her breath tightened, speeding up at the sight of the extensive scorch marks covering the walls and ceilings of the foyer and the heavy layer of waterlogged soot coating the floorboards in streaks and ashy puddles.

Damn. Forget going slow. Finding something they could use in this mess?

That was going to take forever.

Capelli, however, didn’t seem daunted in the least. “Right.” He slipped off his sunglasses, quickly replacing them with his regular pair. “So the house is two levels with no basement. Our best bet would be to start upstairs and work our way down here. Provided it’s safe to do that,” he added, his gaze lingering in doubt on the admittedly rickety staircase in front of them.

Eh, Shae had seen worse by a mile and a half. “Should be fine,” she said, testing the first few steps to be sure. “I wouldn’t trust what’s left of that railing though.”

Dodging the look of disdain flickering over his ridiculously handsome face—God, messing with him was kind of fun—she led the way to the top of the staircase. “So why start upstairs when the bodies were found on the first floor?”

The question seemed to distract him from his irritation well enough. “Because the bodies were found on the first floor.”

“Ah,” she said after a beat of confusion. “You want to rule things out before you start ruling things in.”

“Exactly.”

Shae looked down the narrow upstairs hallway in both directions, measuring the condition of the walls and floors with a careful glance. Two doors on either side, both spaced almost evenly apart, one of which might yield the needle they were looking for and the rest of which would just be a whooole lot of haystack.

Game. On.

Pushing up the sleeves of her navy blue RFD jacket, she led the way down the hall leading toward the Delta side of the house. “Hawkins and Dempsey did search and rescue up here. They didn’t report anything unusual, but the place was burning pretty hard by the time we rolled up.”

Capelli nodded, following her into the room at the far end of the hallway, which turned out to be a small bedroom. “So I see.”

“These scorch marks are pretty consistent with a fire traveling up from the main floor.” Shae pointed to the grimy baseboards, tracing the damage up the walls with a sweep of her finger. “All the burn patterns in here are actually pretty textbook.”

She noted a couple of other details, none of which made her alarm bells start clanging. Luckily, the fire hadn’t destroyed everything in the room. Unluckily, the place had been so sparsely appointed from the start, with just a bare, soot-smudged mattress in the middle of the room and a battered nightstand bearing a lamp, a couple of empty Red Bull cans, and some ruined drug paraphernalia, that it was pretty much a useless victory.

They made quick work of scanning the rest of the rooms upstairs, all of which yielded the same amount of nada in terms of both evidence of arson and clues that might tie in to the murder. By the time she and Capelli made the return trip back down to the main level, Shae’s chest bubbled with frustration.

“Well, if ruling things out was your goal, then you just hit a grand slam,” she grumbled, her boots shushing over the ash-covered floorboards at the bottom of the steps in the foyer.

Capelli lifted one shoulder halfway before letting it drop. “I wasn’t expecting a whole lot upstairs. And anyway, we did learn something important about the fire while we were up there.”

Doubt tugged the edges of her mouth into a frown. “What’s that?”

“It isn’t where it started. Which means…”

Shae’s heart kicked against the crisp white cotton of her uniform shirt. “It had to have started down here.”

“And that’s why I definitively rule out the least likely possibilities first. It’s almost always easiest to do.”

“God, you really are Starsky,” she murmured, turning over the methodical process in her head.

But Capelli dismissed the notion before the words had even fully disappeared into the smoke-stale space between them. “I’m on the RPD’s payroll, but I’m not a cop. This is all just part of my job. Speaking of which…” He gestured to the Bravo side of the first floor, and Shae blinked herself back to the task in front of them.

“Right. I did the search on this side of the house.” She walked into the first room, her thoughts shifting through everything she could remember about the call. The space was veiled in shadows thanks to the boarded-up windows over her shoulder, but of course, Capelli was prepared.

He clicked the button on the Maglite he’d produced from his jacket pocket. “The damage is definitely more extensive down here,” he said, swinging the beam slowly over the room to illuminate it fully. Angry black scorch marks marred the walls in more places than not, and what the furniture had looked like in its glory days? Yeah, that was anybody’s guess.

“Yep,” Shae agreed, taking one last look at the charred remains of the couch now sitting crookedly in the middle of the room. “This was already burning heavily when I did my sweep, too.”

“And you found Richardson in here?” Capelli’s footsteps echoed in muted thumps as he moved into the next room, which held a lot more natural light thanks to the one-way trip the curtains had taken to the floor courtesy of the flames.

Shae nodded, her memory churning along with her gut. “Right by the table.”

“I’m assuming that’s what this was.” He gestured to the ash-covered kindling littering the far wall. The chemicals Shae had seen when she’d last been there had all been removed as part of hazmat protocols. Not that she was surprised—with how flammable they were, leaving them anywhere close to the scene would’ve been a surefire recipe for a flare-up, even once the fire was technically out. But from the warped and buckled floorboards to the fire-ravaged drywall both beside them and above their heads, the sheer damage to this whole section of the room might as well have been a fifty-foot neon sign.

The fire had started here.

Shae’s heart began to pound, her gut locked with certainty. “Yes. This part of the room was burning the hardest. See where the fire ignited this wall here, then traveled up to the ceiling and continued over to the wall over there?”

“So this is almost certainly the point of origin,” Capelli said, his voice so quiet that he seemed to be talking more to himself than to her.

But she answered him anyway. “It is. If someone mixed the chemicals improperly and left them over one or more of these portable burners long enough”—she pointed to the barely recognizable black metal stands that had been washed to the corner of the room, ruined heating coils and frayed electrical cords set beneath each one—“it would have definitely ignited a fire that would leave burn patterns exactly like these.”

Capelli’s eyes moved over the room with such deep concentration, Shae would swear he was memorizing every detail. Finally, he looked at her and gave up a slow nod. “I guess there’s really just one question left to answer then.”

Her brain filled in the blank at the same time he said, “Is there another point of origin that would make this fire arson?”

With care that bordered on excruciating, Capelli retraced his steps to the front of the house. Although she had no idea how, Shae resisted the urge to elbow her way around him, forcing herself to slow the thrum in her chest and the anticipation in her veins as best she could by double-checking their surroundings for anything she might have missed. The process yanked her back to the last time she’d been here, her memories combining with the adrenaline already doing its very best to commandeer her senses. Finally, they made their way through the foyer and into the other side of the first floor, her breath catching tight in her lungs at the sight of the scorch patterns—some scattered, some in clusters, all dark and destructive—covering nearly every surface. Shae’s chest squeezed harder at the wide, gruesome stain on the floorboards where Denton’s body had been, and a sheen of cold sweat bloomed between her shoulder blades, causing her uniform shirt to hug her skin.

She’d forgotten, not accidentally, how much blood there had been. The sticky press of her gloves against her palms as she’d adjusted her grip on Denton’s body to keep her hands from slipping. The coppery smell, like a bag full of dirty pennies, that had punched her in the throat the second she’d taken her mask off.

The bones of Denton’s spine, four of which she’d been able to count with ease through his gaping, gory wound when she’d finally laid him on the gurney outside the house.

Shae tore her eyes from the floor just in time to see Capelli looking not at the scene, but at her instead, and she shook her head before he could verbalize the are you okay clearly brewing on his lips.

Breathe in. Breathe out. Do your job.

Help solve the case.

“Slater found Denton’s body over here. Obviously.” She swallowed and turned to study the rest of the room, the task calming her brain even as it kept her pulse at a steady clatter. “He was shielded from a lot of the fire by that armchair, but it also made him a little harder to see at first.”

“CSU went over that part of the room pretty carefully,” he said. His voice carried a slightly softer tone than usual, and despite how desperately she wanted to help with the case, God, she was grateful as hell not to have to relive the memory of dragging Denton out of there.

Marshaling her thoughts back to the fire itself, Shae squinted, trying to firm up the picture in her mind. “Most of my focus was on Slater when I came back in here, but I definitely remember that this table had the same kinds of chemicals all over it as the one in the other room.”

She reached out to skim her fingers over the warped surface of the tabletop, which had only sustained less damage than its counterpart on the other side of the house because it was a heavy plastic and metal folding table rather than made of wood. “There,” she breathed, pointing to a huge, upward bloom of fire damage on the interior wall. “Yeah, look. There must have been another one of those portable gas burners plugged into this outlet.”

Shae scanned the wreckage in the room, her heart beating faster in anticipation, and come on, come, on—ah! A mangled unit with four connected burners lay upside down on the floorboards a few feet away.

Her brain spun. “If someone left enough chemicals over the burners in both rooms, then threw some more around as accelerant, that would explain how the fire spread so quickly.”

“Spreading out the chemicals does make sense,” Capelli said, his stare moving meticulously over the table and the burn patterns behind it. “Less risk that the fire would accidentally cause an explosion that could hurt the person setting it that way.”

“Exactly,” Shae said, undisguised excitement kicking through her chest. “So do you think maybe this was some kind of argument gone wrong? Lawrence kills Denton, then sets fire to the house to try and cover up the murder, only he gets over-zealous with the chemicals and eats too much smoke before he can get out?”

Capelli frowned. “I think you’re jumping ahead of the facts.”

“How’s that?” She slid a hand to the hip of her uniform pants. “With how closely these burn patterns match the ones on the other side of the house, there’s no way there weren’t two points of origin for this fire. It’s definitely arson.”

Although Capelli didn’t argue with her, he also didn’t agree, and for the love of fucking pockets, what more could the man want by way of evidence?

“That doesn’t mean the L-Man set it, or that he killed Denton. He didn’t have any blood on his hands or clothes. Still, there is more damage on this side of the house.” Again, his brows bent in concentration, his shoulders locking into a broad line as he continued to examine the room. He seemed more lost in thought than scrutiny, but damn, he sure didn’t pull up on his intensity in the switch.

“There are two points of origin, but they couldn’t have been set simultaneously by one arsonist. It’s likely that whoever did this started the fire over here first, which gave it more time to burn. That still makes Lawrence the most likely suspect,” she insisted. “Either that or you’ve got the world’s luckiest criminal on your hands.”

Sure, the chemicals used to cook meth were toxic, but the chances that a third party could kill Denton, set the fire, and ensure that Lawrence would be overcome by the fumes and smoke before he escaped the house? Capelli of all people had to know how steep the odds were on that one.

A soft chime interrupted whatever he meant to say in response. He slid his cell phone from the back pocket of his jeans, giving her a fast glance of apology as he pressed it to his ear, and after a few minutes’ worth of “mmm hmm”s and “I see”s, he lowered the phone with an exhale.

“Actually, it looks like our guy has more brains than luck after all. The ME just finished the autopsies, and it looks like both Richardson and Denton were pumped full of sufentanil just before they died.”

“Sufentanil?” Shae blinked. “What is that, specifically?”

“It’s a synthetic opioid that’s used as a painkiller or an anesthetic in small doses,” Capelli said.

She pushed past the confusion in her brain, thinking and processing, and oh God. “What about in larger doses?”

“In larger doses, it would render a person fully unconscious—even if the building they were in was burning down around them. Which means not only were Lawrence and Denton both murdered and this fire was set by a third party…”

Dread centered itself behind Shae’s breastbone, digging in deep. “But whoever did it is still out there, and we have no idea who he is or how to find him.”