There was a deafening, rolling boom of thunder that Dean felt in his ribs, then a loud pop, and then darkness so complete that it took his breath away.

After a few brief seconds in the quiet that followed, Dean cleared his throat. "Well. Good thing we keep candles around. Who wants to go find them?"

Grumbling, Sam flicked to the flashlight app of his phone, the screen illuminating him in its harsh blue light as he carefully navigated the hazardous obstacle course the bunker had become in the darkness. In minutes, he threw a handful of cheap tea lights on the table before slumping back into his chair again.

"What's got your panties in a bunch?" Dean asked as he dug around in his pockets for a book of matches.

"Laptop battery is nearly dead," Sam replied irritably. "There's no outlet the cord can reach. And so of course the power goes out." He poked disconsolately at the keyboard. "Useless anyway. Internet is out, too. Obviously."

"God forbid we have to actually talk to each other," Dean said. The white wicks of the candles crackled as they took the flame from the match, the flame shrinking tiny and dim as the heat melted a pool of wax, then strengthening as it drew the fuel up the wick. He lit five of them, clustered into a rough circle in the middle of the table, before the match burned close enough to his fingers to make him reflexively shake it to extinguish the flame.

"What's there to talk about?" Something was clearly bothering Sam, something more than just the unexpected lack of electricity. "We've talked circles around this thing. It's not a wendigo, it's not a vampire, it's not a drake -"

"Dude, chill," Dean said, holding up a hand. "We'll ID it tomorrow. We've got three days before it hits again, if it follows its pattern."

Another clap of thunder unfurled overhead, echoing into the corners of the library. The bunker was built too thickly for Dean to hear the sheets of rain that must be falling. He dimly considered opening up the front door, just for a moment, to hear the pound of the rain against the gravel.

"What happened?"

Dean whipped his head around. The ambient light from the candles on the table didn't reach very far, and Cas was just a dark shape against a darker background. "Power went out. Thought you were asleep."

"The thunder woke me." Cas shuffled to a chair by Dean and lowered himself into it, yawning widely. Dean smirked; Cas's hair stood up at wild angles on one side of his head, and coupled with the flannel pajama bottoms and too-large gray tee shirt, he looked every inch like the sleep-rumpled human he now was.

"Well, I'm going to bed," Sam said, closing his laptop with a little more force than necessary. "No point in pulling an all-nighter if our entire capacity for research is down and out." He thumbed his phone on again and nearly stalked from the library.

"What's wrong with him?" Cas asked, brows knitting together in puzzlement. Dean waved a hand.

"He's pissed because whatever this thing is, it got a girl named Jessica." Dean watched as the aura of blue light from Sam's phone disappeared up the stairwell. "Opened some wounds he thought were healed."

"Jessica was his girlfriend." It wasn't a question, exactly, but Dean nodded.

"I liked her. Never really got to know her - but I liked her." Dean shrugged. "It was a long time ago. Don't think he expected it to still be able to come back to haunt him."

Cas nodded slowly, eyes drawn to the steady flames of the candles. "Do you still think of Lisa?"

The name plucked at something in Dean's chest, an almost tangible pain that he swallowed against. "Sometimes. Just, you know - to wonder if they're happy. How Ben's doing. He'd be - shit, he'd be fifteen now." He swallowed again, his own eyes drawn to study the flames as they danced on their wicks. "Time flies."

There was a smooth silence as Cas drew a breath. "The last time I saw them...they were doing fine."

Dean's eyes flicked over to Cas in surprise. "You saw them?"

Looking almost embarrassed, Cas shrugged. "I knew you couldn't. So I - I'd occasionally make sure everything was all right."

"And?" Dean didn't know why he was so tuned into Cas's every word. That was a part of his life he'd walked away from so long ago that it barely registered as having been his life. It hadn't been, not really; that sort of comfort and stability didn't belong to him. He'd been able to pretend for a few short glorious months, though, and apparently he still hadn't let them go.

"And they were fine." Cas glanced over at Dean before returning his gaze to the candles, but it was unfocused as he licked his lips. "She was engaged. He seemed like a good man. Ben liked him."

It was probably the thunderclap overhead that impacted so solidly against Dean's chest. "Well. As long as Ben likes him. And Lisa too. Of course." He was still holding the burnt-down matchstick, turning it over and over between his fingers, fraying the edges. The charred end rubbed black against his fingertips.

"Of course."

One of the wicks popped. Another low rumble overhead, not as dramatic as the others but long and pervasive, underlined the silent darkness that the candles pressed back.

"I've always liked candles," Cas said suddenly, reaching out to idly flick a finger through one of the flames, too quickly for it to do any damage. "Humans have endlessly been warring against the night. Candles always seemed like a...gentle compromise."

Cas was apparently in one of his poetic moods. It was usually best to just let him talk. His voice became smoother, somehow, when he embarked on his infrequent soliloquies, and Dean found himself relaxing as he let it roll over him like warm honey.

"Electricity banished it. Once there was electricity, the night was no longer a thing that could rule humanity. But candles...candles run out. They're a bargain with the darkness, that they can keep it at bay until the last flicker of flame, and then they must surrender to what humans do in the darkness."

Dean snorted. Cas shot him a long-suffering look. "Sleep, mostly," he clarified with emphasis, "although, yes, there are other things for which humans tend to prefer darkness."

Cas lapsed into silence, and Dean felt a slight pang that his childish outburst had stemmed the flow of words.

"You always reach for the light," Cas said suddenly, as though he was simply continuing an entirely different conversation. "Put a man in a dark cave and put a candle some distance away from him - ten feet, a mile - and he'll always venture towards it. Even when it goes out, he'll keep going in that direction. It's as though humans are starved for light."

He passed a finger over a flame again. "And you don't want to go where light can't live. You'd send candles into mine shafts and if they were extinguished, you wouldn't follow." A small smile tugged at the corner of his mouth. "It ended up being for a practical reason, of course. If a candle couldn't burn, there wasn't any oxygen. Still. Where a candle couldn't burn, humans wouldn't follow."

Dean watched the play of Cas's fingers over the flames, all supple dexterity and smooth skin sliding over tendons, pale half-moons at the base of each fingernail. Entranced by their movement, it took a moment before he realized Cas was talking to him.

"What?" Dean asked, wrenching his mind away from his contemplation.

"I said, do you remember when I raised you from Hell?"

The non sequitur made Dean blink. "Not really." He licked his lips. "I've done my best to forget everything that happened near the end there."

Cas nodded. "Understandable. You'd...fallen pretty far."

Dean shifted in his chair. "I remember a light. Bright. Brighter than anything I'd ever seen, or anything I've seen since."

Cas nodded again, more enthusiastically. "You reached for it. In the darkest place a human can be - the darkness of the lost soul - you reached for the light. For me." He abandoned his study of the candle flames to look directly at Dean, eyes piercing and glittering in the candlelight. Dean met his eyes and couldn't look away. "I did grip you tight, but - you met me halfway."

The intensity of the moment wound around Dean and he was afraid to blink, afraid to banish it, afraid to even breathe. Cas was the one who broke the contact, turning his face back to the center of the table, the candlelight throwing the planes of his face into sharp relief. "And...it seems as though we've been reaching for each other ever since, whenever we need a light." He licked his lips, his eyes falling out of focus again. "Even when the light wasn't there. We still ventured towards it."

Dean realized his mouth was hanging open and he snapped it shut. "You go weeks saying ten words - usually 'Dean, don't' or something of that ilk - and then..." he made an inarticulate gesture between them both.

"I usually can't get a word in edgewise," Cas said, the introspective tone dropping away to reveal the wry twist with which he said the words. "It gives me a lot of time to think about what I'm going to say when I get the chance."

"So you were waiting for us to light candles to say all this?" Dean asked, trying to force himself into the banter of jovial rejoinder and failing.

"No. The candles were convenient, but..." Cas sighed softly. "I've been thinking a lot about what it means to be human. Reaching for the light, even when it's not there." He glanced back over at Dean again, and his eyes held Dean immobile. "And I realized I've been doing that for a long time now. It made me wonder if I've had a touch of human to me all along."

Dean cleared his throat, very aware of his heart beating loudly in his ears. He looked down; at some point they had shifted in their chairs and were sitting sideways, facing each other, knees inches from touching. "I'm not sure what you're trying to say," he lied.

He made the mistake of looking up and was trapped again by Cas's azure gaze. "Metatron made me human. But you'd already showed me what being human meant. I...owe my humanity to you."

At the edge of his vision, Dean could see Cas's hand twitch, as though it would reach across the space between them. It made his heart step sideways in his chest, breath expand in his lungs until he let it out in a soft whoosh, tearing his eyes away to look somewhere, anywhere, but at the man in front of him. His mouth opened uselessly, words an incoherent tumble in his mind that he couldn't fathom into sounds.

Somehow - because it seemed as though it was always where his eyes landed - he was looking at Cas again, lost in the blue that was the most telling of Cas's origins; human eyes had never been so weary and weighted, so burdened with an unspeakable sadness.

They weren't sad now. They were soft - not smiling, because Dean had memorized every slight wrinkle around Cas's eyes when he smiled, but content.

With a smooth movement, Cas reached up to lick his fingers. Dean blinked, not expecting the incongruous motion at all, and before he could arrange his face to reflect his puzzlement, Cas reached over and snuffed the candles, one by one.

The darkness was absolute, a shroud that pressed against them in its totality. Dean could see sparks of light flashing before him as his eyes tried to reconcile the sudden absence of light. Even the thunder seemed to respect the sudden hush, giving one last low rumble before fading.

"One thing humans have forgotten, since they learned to avoid the darkness," Cas said softly, and it almost seemed as though his voice was coming from all angles without the visual to attach it to, "is that the light is for - it symbolizes truth. The darkness was always for secrets." There was the sound of him wetting his lips. "Secrets might be true, too. But they're easier to say, in the dark."

Dean swallowed. Secrets. He lifted a hand from his knee and the burnt matchstick tumbled from his fingers as he groped forward. His hand brushed another and he recoiled slightly before their fingers slid together. Just two fingers, barely curled around three of Cas's, warm and calloused, with scars on the knuckles and seeming more sensitive than they'd ever been.

Something enormous rose at the back of Dean's throat and he coughed to clear it. "Everything that's good in me - I either got it from Sam or you." There was no point in trying to make eye contact, not now, so Dean kept his eyes trained on where he knew his hand was, fingers trembling slightly. "So...whatever light you're reaching out to...I figure, a lot of the time, it's your reflection."

The long moment settled about them like dust motes, until a thumb began to lightly stroke the first knuckle of Dean's fingers. The touch left a silken trail of remembrance that made the hairs at the back of Dean's neck prickle. "Have you ever put two mirrors in front of each other?" Slight pressure, not even a squeeze, and then a twist, intertwining the fingers effortlessly. "They reflect back and forth forever."

With no light to see it by, the secret wove through their touch, strengthening with every heartbeat. And in the mystical power of darkness over humans, they were simultaneously too cowardly to say anything further to break the silence, and brave enough to endure it and everything it contained.