Author's note: all credit to Jeremy Carver and SPN writers for the opening scene, which was transcribed directly from episode 8.23. This story was written to fill a square on my hc_bingo. (See end to see what the square was.)

Blood dripped steadily from the deliberate cut in his hand. Sam clenched his fist, but the stream flowed unchecked, like molten lava that seemed to be surging through his veins.

"You want to know what I confessed in there? What my greatest sin was?" he demanded harshly, stabbing a finger toward the confessional. "It was how many times I let you down." Raging emotions had fueled the gesture, but Sam's strength was fading fast. He wobbled on his feet and his arm dropped. "I can't do that again."

Dean closed his eyes, stricken. "Sam—"

Sam shrugged bitterly. "What happens when you've decided I can't be trusted again? I mean, who are you gonna turn to next time instead of me? Another angel? Another—" His voice caught and broke. "Another vampire?"

Dean jerked at that, but Sam pushed on. "Do you have any idea what it feels like to watch your brother just—"

"Hold on, hold on!" Dean couldn't listen to any more. Couldn't let Sam believe this was what Dean felt about him, not for another second. "You seriously think that? Because none of it"—His voice grew even rougher—"None of it is true."

Sam flinched, eyes shining with tears as he struggled to believe.

"Listen, man, I know we've had our disagreements, okay?" Dean went on. "Hell, I know I've said some junk that set you back on your heels. But, Sammy..." he pleaded. "C'mon. I

killed Benny to save you. I'm willing to let this bastard and all the sons of bitches that killed Mom walk because of you. Don't you dare think that there is anything, past or present, that I would put in front of you! It has never been like that, ever!" Ragged emotion, raw honesty, flooded his voice. "I need you to see that. I'm begging you."

Sam's hand shook and more blood ran from his fist to the floor. His voice trembled. "How do I stop?"

As if those words had unlocked a door between them, Dean took a step toward his brother. "Just—let it go."

"I can't." Sam shuddered. "It's in me, Dean. You don't know what this feels like."

Dean reached out and carefully took Sam's left hand. A memory flared from the depths of Sam's shattered past, and Sam saw another time Dean had held that hand, blood seeping from a lacerated palm. He'd known then that Dean was his anchor. Dean was Stone Number One.

He remembered, and so he stood still, yielding, trusting, as Dean whipped out a bandanna and wrapped it around the open wound.

"Hey, listen, we'll figure it out, okay? Just like we always do. Come on." Dean tugged him close, pulling him into a desperate hug, as much to hold him up and share his strength as to give him comfort. "C'mon. Let it go, okay? Let it go, brother."

Sam breathed. The fire in his veins, the incandescent glow and the burning sensation began to fade. "Hey, Dean." Sam stepped back to show him, holding out his forearms.

"See?" Dean reassured him, and the words made Sam feel both stronger and more drained. The relief in his shaky exhale was almost palpable. But then—

Sam cried out, crumpling in agony.

"Sam?" Dean caught him before he fell. "I got you, little brother." He hauled Sam outside the dilapidated church, guiding him to what had always been more of a sanctuary to the Winchesters than anything else: the Impala. "You're gonna be just fine," Dean murmured, unconvincingly, as Sam dropped to the wet ground beside the car, writhing in pain.

"Sam? Sam!" Dean turned his gaze skyward in desperation. "Cas? Castiel! Where the hell are you?"

There was no answer. Just the sound of his brother wheezing in increasing respiratory distress.

"Sammy!"

Overhead, the sky suddenly began to fill with shooting stars. Only—Dean knew that wasn't what it really was. "No... Cas…."

The ground reverberated at the impact of something crashing to the earth.

"What's happening?" Sam gasped, looking up.

"Angels," Dean answered, awestruck. "They're falling."

"No!" For a moment, Shelly couldn't breathe past the lump that felt like her heart was lodged in her throat. The forbidden book fell from her nerveless fingers to the floor with a soft thud.

Surely her folks wouldn't hear that sound and come investigate. They were very strict about what she was allowed to read. But they were also pretty oblivious to everything but their lab work in the basement, and it's not like she'd dropped the Oxford English Dictionary. This was only a paperback after all, and mass market at that. Mass. Heh. If black holes had really swallowed up all the print media, as her parents liked to say, it wouldn't have to be a very big one to consume every copy of this series of books. She grabbed a marker and began to scribble. As the mathematical symbols flew, her shoulders straightened and her breathing slowed and settled. Whenever her teenage emotions threatened to overwhelm her, there were two things she could always count on her to distract her and bring her back to an even keel. Her whiteboard was one of them.

Shelly nodded to herself, content to distract her thoughts with barely related number-crunching. The smallest black hole would have a mass whose Compton wavelength and Schwarzchild radius were equal…. And even the smallest black hole imaginable would accommodate the miniscule circulation of that obscure and almost-impossible-to-find-even-on-the-black-market series of books: Supernatural.

Tears threatened to well up again, as she ached for Sam and Dean Winchester.

Calculations finished, she lowered her arm, and as she did she felt something cold and wet swipe against the back of her hand. "Oh, Engelberger!" she sighed. "How do you always know when I need you?"

A pair of warm brown eyes stared up at her adoringly, and Shelly sank to her knees on the rug and buried her fingers in the dog's thick ruff. At her touch he lunged forward, knocking her on her ass so there would be a lap to climb into, heedless of the fact that he'd never been small enough to fit. At last he got settled with his head on her knee and curled up as close to Shelly as he could get, his tail thumping against the floor.

This was even better than science at soothing her. Engelberger was someone to actually talk to, even if he didn't answer. He was there, and that was enough. At times she didn't know what she would do without him.

"I hate hiatuses between books!" Shelly swiped at her runny nose with the back of her hand. Engelberger was never grossed out by anything she said or did. "I've got search engines running round the clock for the next book, but I haven't got any leads at all yet. I have to know if Sam and Dean are going to be okay!"

The book lay cracked open and facedown on the ground an arm's length away. The cover showed a creepy abandoned church. The sky behind it was swollen with dark, ominous rain clouds. In the foreground a sleek black Chevy Impala appeared to have just pulled to a stop in front of it. The book's only dash of color was the car's brake lights, gleaming red like fresh blood.

The image seemed to mock her. She had no idea where the church was. Wherever they were, it was far from help, and whatever was ailing Sam couldn't be fixed by a hospital. Shelly was sure of that. They had to get back to the bunker. They just had to.

As if sensing her distress, Engelberger shuffled closer. She could feel his heat against her, warm and comforting. "Sam sure would love you," she told him, massaging his ears, and he closed his eyes, in apparent canine ecstasy. "Remember when Sam was a teenager, he ran away and adopted Bonesy for a while," she prodded, because she had read him all her favorite parts. "And later, when he had a dog named Riot…." There were more scenes of Sam with dogs in the books, she knew, but it didn't matter.

What mattered was that right now Sam was suffering, and Dean no doubt battling the gritty-eyed exhaustion that came from driving hours without rest to get them to the only haven they had left.

Right now is such a relative term, Shelly mused. Especially when her parents had a functioning particle accelerator in the basement, capable of time travel. Of course, it wasn't like she could just drop by the Men of Letters bunker in Lebanon, Kansas however many years in the past Sam and Dean were. People couldn't really go back in time. Everyone knew that. Still….

One hand idly stroked Engelberger's broad head, while she stretched the other out to pick up the book. Settling it on her knee, she brushed her thumb across the title. Sacrifice.

Not just the current story—it could really be the name of the whole series, she thought. Time and again, Sam and Dean risked everything, gave up everything, for total strangers in need of help. And most of all, for each other.

And sometimes… they made her wish she could be a little more selfless, a little more compassionate, a little braver herself.

The metaphoric light bulb she'd been trying to ignore over her head blinked insistently. "What do you think, Engelbengle?" she murmured, massacring his name affectionately. The dog encouraged her, tilting his head so she could scratch under his chin, and she knew he was agreeable to her plan. He always indulged her every whim. It was in his programming.

She clutched him tight for a second, then pulled back to just drop her forehead against his for a moment. He gave her chin a lick and she sighed. This might just be the hardest thing she'd ever done.

Epilogue:

Shelly always thought it was a cliché to read about someone's hands shaking as they picked up a much-longed-for object. But as she lifted the small package from the day's mail, she observed that it was a very real phenomenon. Her search for the next Supernatural book had finally paid off and was about to reveal what happened next.

Dean needed both hands to keep Sam upright, so as he hauled his semi-conscious brother out of the Impala it was a relief to see Kevin standing at attention at the open door to what Dean in better moments casually called The Batcave.

"What—" Kevin called out.

"Later!" Dean growled. He shouldered past and staggered toward the hall that led to the bedrooms.

"Dean?" The single word was croaked softly by his ear, and Dean felt Sam try to take more of his own weight as he struggled to take in their surroundings.

"It's okay, Sammy. We're home." Dean nudged the door to Sam's room open with his boot and steered Sam toward the bed. Kevin trailed behind them.

Sam's room was more ascetic than Dean's. It seemed that Sam had never made the effort to personalize it with treasures like Dean had: no favored weapons on the wall or photos on the dresser. But that didn't mean this didn't feel like home to Sam. The library here was what made his eyes light up. A pile of books on the floor beside the bed connected Sam to the source of his comfort.

But right now he didn't have the strength to lift a book, or the clear-headedness to read.

Sam wrestled free from Dean's hovering to toe off his shoes, then sank back against the pillow, too weak to keep up the pretense that he was fine. Weeks of The Trials had carved gaunt hollows in his cheeks, and shivers now wracked his long frame. Dean put the back of his hand against Sam's sweaty forehead and he didn't bat it away—not a good sign.

"Kevin, get me the thermometer and get ready to fill the tub with ice, just in case," Dean barked.

Sam curled on his side as he was wracked by cramps. His breath came out in a hoarse wheeze, panting too fast.

"No ice. 'm already c-c-c-old," he complained. His fingers plucked weakly at the edge of a blanket as the spasms eased for the moment.

"Dean? Can I talk to you for a minute first?" Kevin asked, edging toward the doorway.

Dean lingered, swaying with exhaustion, but at Sam's feeble shooing motion, he nodded and followed Kevin to the main room. "If the fever's not too high, we can skip the ice bath. But we gotta get him warm and stable," Dean started. "Get him breathing slow and easy—"

A shadow moved under the map table.

Dean reached instinctively for a weapon, but Kevin grabbed his wrist. He crouched down low and held out the back of his free hand.

"C'm'here, boy."

And out from under the table crept… a dog.

"Kevin, what the hell are you thinking? Bringing a mutt—"

"Don't look at me. It's not my dog, Dean. It's apparently yours."

Dean stopped in his tracks. Kevin took hold of the dog's collar and spun it round until a rectangular metal tag could be read: interim property of Dean and Sam Winchester.

"The hell?" Dean repeated.

"There's more." Kevin pulled a small pouch out of his pocket. "This was attached to his collar when I found him.

Inside the bunker, I might add. There's a note here. Addressed to you."

Dean stepped forward to take it, and their uninvited guest broke into a sloppy doggy grin, his tail broadcasting his excitement.

A sheet of paper, tightly folded, was tucked inside the packet. With another glare at the dog, Dean unfolded it and read.

Dear Mr. Winchester. Or Dean, I guess.

You don't know me, but I know you and your brother. From the books. I know you know about them, but don't worry, I'm not a stalker. I know what happened in The Trials, and I guess Sam is in pretty bad shape now. I wish I could do something to help. You don't know how many times I've wished there would be a story where people actually thank you, or even better, help you. But I guess that wouldn't make for a very suspenseful plot, huh?

If I recall correctly, you may not know that more books have been written about you and your brother in the years since Lucifer got locked away. I have the feeling it's a different writer now. Maybe more than one. (Kevin's a prophet; I wouldn't be surprised if maybe he writes some of the books. But don't tell him I said that!)

Dean paused to peer at Kevin over the top of the page, but the boy just gave him an inscrutable look in return.

Anyway, here's the thing. You obviously already know about time travel. But it's not just spells and angel mojo. In your future, it's a scientific reality. Not living things, but we can send devices back in time. And retrieve them.

Well, I was thinking, how I wished I could do something for you and Sam, after all you've done for us. I mean, I wouldn't be here—humanity might not still be here—if it weren't for you two.

I can't do much. But I can share my dog. I think maybe he'd make Sam feel better for a little while. And he's an android, so he won't be any trouble. Doesn't need food or water or bathroom privileges or walking or anything. His name is Engelberger, but he'll answer to just about anything and he'll just love you in return. I programmed him; I should know.

And Dean—I know how you like to tinker with mechanical stuff. Please don't break my dog.

You should know that time travel (the scientific kind, anyway) has a built-in boomerang effect. Anything sent out automatically comes back in two weeks. It's a failsafe; I guess someone figured that reduces the risk of being discovered and affecting the time-space continuum or something. I don't know exactly. I'm just a kid with a particle accelerator in my basement. (Well, it's my parents'.)

What the… Dean's mouth shaped the words but no sound came out.

I hope Engelberger helps you guys heal up. I know he helps me when I need—well, to not feel so crappy, I guess.

And Dean? Try not to worry too much. Spoiler alert: the world must not end on your watch, because I'm here, lending you my dog. Right?

Take care of yourselves. And each other!

Love, Shelly Cooper

Dean glanced down at the dog, which looked as real as any dog he'd ever seen. "Go find Sammy?" he suggested with a helpless look on his face.

Englebungle, or whatever his name was, took off like he'd just been set off leash, nails clattering against the floor tiles in his eagerness to obey.

"You sure that's a good idea?" Kevin asked. "The last time Sam got up close and personal with a dog, I think he had a hellhound trying to rip his throat out. He might not react well—"

"Uh…." Dean's brows lifted, and then he was tearing out of the room, Kevin at his heels.

They needn't have worried.

"Who's a good dog, eh?" Sam was crooning softly. The dog was nestled snugly against Sam's side, sprawled in bliss as Sam scratched his belly. Sam's voice sounded less wheezy, his lungs not laboring so hard, and his shivers seemed to slow even as they watched.

Sam raised his gaze to his brother as Dean skidded to a stop in the doorway. "Who is this? Where'd he come from?" he asked, but barely got the question out before a yawn took over.

"If I told you now, you'd probably think you were delirious," Dean said. He stepped forward, scratched the soft fur behind dog's ears, and then let his hand drift to Sam's hair too. Sam was nearly asleep now, didn't notice.

"Get some sleep, little brother. You're gonna be just fine," Dean told him. And this time, he almost believed it.

~ end ~

Author's note: This story was written to fill the 'robots/androids' square on my hc_bingo.