Somewhere in the middle of Supernatural season five...

"C'mon, Sam!" Dean shouted uselessly to the barely conscious Sam hanging onto his shoulder. Dean hurried him as fast as he could; his sawed-off shotgun gripped tightly in his other hand. He could hear the spirits behind him, but he couldn't see him.

Why did they have to stop and investigate a haunted house? Wasn't knowing that the apocalypse was looming enough?

A force hit both of them and Dean stumbled, dropping his bleeding brother and the sawed-off. Dean was thrown, his head connecting with something solid and sending a spray of colorful stars everywhere. The spirit manifested as a large man, his head bent at an odd angle. Snarling, it lurched towards Dean.

"Hey! Ugly man!" A high-pitched voice called and the shotgun fired.

The spirit scattered.

Dean shook his head, trying to clear it. He wasn't sure if he was seeing double or if there were two of the short rescuer running to his side.

"Where'd he go?" the high voice asked. The two girls merged into one with big brown eyes and dark pigtails poking out from under a dirty hat. She crouched beside him, her eyes moving around the room.

Dean looked around. Sam was slumped about ten feet away, his shoulders falling. Wait...no, all of him was falling.

"Sam!" Dean screamed, struggling to his feet, but the blow to his head made the room spin and he fell to his knees.

"Look out!" the girl shrieked and the shotgun went off again.

Sam fell out of Dean's sight. Dean dragged himself over to where Sam had vanished. The floor was solid.

"Mister, we need to go!" The girl was tugging at his leather sleeve.

"SAM!" He shouted.

"You can't save him if you're dead!" The girl responded, pulling more urgently. "I'm out of bullets at that thing is coming again!"

Dean gripped her shoulder and let her help him to the door. Which was locked, naturally.

"Doctor!" The girl screamed, pounding the door. "Doctor! Hurry! AHHH-!" The spirit had grabbed her legs and was pulling her back.

Dean grabbed her dark hoodie, throwing his weight against the ghost.

Her fingers dug into his arms, her eyes wide.

The door burst open, and rock salt scattered the ghost. Dean tucked the girl under his arm and ran for the Impala. He glimpsed a man wearing a trench coat following them down off the porch. Dean set the girl on Baby's hood and leaned forward to rest on his knees.

"Shouldn't we keep going?" The girl asked, looking between Dean and the other man.

"Classic haunting. Something's holding that spirit in that house," the other man pointed. "Can't come outside, though." He had an English accent.

"Haunting, like ghosts?" the girl asked.

"Yeah, exactly like a ghost," the man replied, reaching over and tweaking the bill of her hat.

"Sam got grabbed," the girl said, her voice very serious.

"Who's Sam?" the man asked, all playfulness gone from his voice.

"My brother," Dean answered, taking the sawed-off from the girl and reloading it.

The man nodded, his hands shoved into the pockets of his blue suit. The girl swung her shoes and looked back at the house. Dean figured she couldn't be much older than eleven. Normally he'd be concerned that her shoes would ding his paint, but considering she'd just saved his life he figured he could make an exception once.

"Is the ghost going to kill Sam?" she asked, her voice betraying none of the fear Dean would expect from a girl her age in this situation.

The man pulled a device from his pocket and aimed it at the house. "I'm still detecting one life sign," he remarked, tucking it back away.

"Then how are we going to save him?" the girl asked.

"We're not," the man turned and walked away. "Come on, Clementine, it's time we move on. We don't want to miss the asteroid showers off Ziggio two!"

The girl kicked herself off the hood of the Impala and walked the opposite way, to the bag of guns Sam had dropped when they'd heard the screaming from the house. She opened it the rest of the way and pulled out a handgun and checked it with surprising ease. The man watched her with a scowl.

"Thanks, but I got this," Dean told her, pulling the gun out of her grip.

"Your brother got grabbed," she said, looking up at him with serious brown eyes. "You don't wanna lose him, right?"

Dean blinked, and looked away from her intense stare.

"I'm Clementine," she took the gun back from him and completed her check. "So...ghosts. I'm guessing bullet don't work?"

Dean shook his head. She'd clearly handled guns before. Maybe she was a hunter's kid like he had been? "Rock salt cartridges, they'll work. Dean, by the way," He offered her his hand.

She gave him a tight smile and shook. Her hand was tiny, but determined.

"Clementine!" The man looked frustrated.

"You go ahead, Doctor," Clementine tucked the gun in the back of her belt in another disturbingly easy gesture. "I'm going to help Dean rescue Sam. It's what I do." There was something biting in her tone.

"Clementine, a spirit like this is angry. He's held on too long, and now he's lashing out at whatever comes near him." The man hurried back, kneeling to look the girl in the eye.

"So protect me," Clementine replied.

They stared at each other for a long moment. Finally, the man stood and shook his head.

"Do you know where he's buried?" he asked suddenly, standing up and turning to Dean.

"What?" Dean asked.

"The remains, I'll salt and burn while you rescue your brother." The man was maybe an inch shorter than Dean, and met his gaze steadily.

"Edgar Tollous, Woodlawn cemetery," Dean told him.

"Clementine, come on," the man held down a hand.

Clementine didn't looked up from where she had pulled another sawed-off shotgun from the bag and was loading it with the salt cartridges. "I'm going in with Dean."

"No!" Dean and the man said in unison.

Clementine stood up and cocked the shot gun. "Dean needs back up, Doctor, and we know how you are with guns." She smiled strangely. "Believe me, I can handle it."

She and the man looked at each other for a moment, and to Dean's shock the man nodded. "Good luck,"

"Wha-? No, I am not taking some kid!" Dean protested.

"C'mon, we don't know how much longer your brother's gonna last," Clementine said, tucking the shot gun into her shoulder.

The man set a narrow hand on Dean's shoulder. "Clementine can handle herself, don't worry." With a squeeze, the man was gone.

Dean shook his head and followed the girl back up onto the porch. The front door swung easily open at her touch.

"That's not good," Dean whispered, taking the lead. Clementine's footsteps were light behind him, and more than once he almost turned expecting a ghost.

The first floor was empty, so Dean led her down to the basement, taking each step carefully. She stopped part way down the rickety steps when he held up a hand. The dirt-floored room was empty. There were no doors out of the room, and Dean bit his lips looking around. He looked back up at Clementine in time to see the spirit approaching her back.

He didn't have time to choke a warning when it grabbed her. To her credit, Clementine didn't so much as scream this time. Instead she twisted, bringing the sawed-off shotgun upward and blasting the ghost between the eyes. The moment she was free she ran down the stairs and behind Dean, her brown eyes wide and her face pale.

The door slammed shut.

"Shit," Dean whispered, setting a hand on Clementine's shoulder.

"Swear," she whispered back, turning such that her back was pressed against his. Ass, that is. God, she was tiny.

"I don't see it," she added in a low voice.

"Son of a bitch is here somewhere," Dean lifted his own shotgun and turned. She turned with him, keeping her back against his.

"I see something," she said. Dean turned; her small finger was pointed at a hole in the wall.

Once she knew he was looking she walked over. It was a tiny hole, half covered by heavy-looking steel sheet. Dean passed Clementine his flashlight and tried to shove the plate away.

"Sam?" Dean shouted.

"Dean!" The reply was weak, but from distance.

"You okay?" Dean measured the hole with his hands. No way he was going to fit through there. "I'm coming, Sammy." He tried futilely to press his shoulder through the hole.

"I can fit," Clementine said, staring at the hole.

"Oh-no!" Dean said.

"Sam's in there, and he doesn't sound good," Clementine replied. "And that plate is bolted in. Can ghosts move people through walls?"

Dean looked down at her. "Sometimes, yeah," he finally answered.

Clementine nodded and swallowed. For a moment an expression of pure terror crossed her face, only to be replaced with one that could only be described as pure stubbornness.

Holding the sawed-off shotgun close, she leaned into the hole.

"Here," Dean pulled a smaller flashlight out of his coat pocket and passed it to her. She handed him the shot gun and pulled out the sidearm, carefully—expertly—balancing both of them in her narrow arms.

She ducked through the hole, and Dean cursed himself as she vanished from sight.

"Sam?" he heard her muffled call after a moment. "Sam, are you in here?" her voice was getting even more muffled.

He heard Sam call something back, but it was too weak to distinguish the words.

"Clementine?" Dean called.

"I'm okay!" she called back. "It opens out ahead...I think this was a bomb shelter!"

"Be careful!" Dean ordered. There was no way he'd be able twist his shoulders through that hole, no less the tunnel beyond it.

A little girl's scream made his heart pound, and the crack of the shot gun followed it.

"CLEMENTINE!" Dean screamed, trying to force himself into the hole and earning a bruised shoulder.

"I'm okay!" Clementine shouted back. "Sam's here. At least I think it's him? He kinda fainted." Her voice got closer and her flashlight flashed down the tunnel. "Was he wearing plaid?"

"Where's the ghost?" he demanded.

"He burst into flames," she said. "Does that mean he's dead? I mean, really dead?"

"Means that your friend salted and burned the bones," Dean replied. "How's Sam look?"

"So...he's not coming back?" Clementine prompted.

"He's gone," Dean replied. "How is Sam?"

"Not great. Wait, I think he's waking up."

Dean looked down at his feet, then:

"Dean?"

"Sammy! Are you okay?" Dean shouted.

"Yeah, I'm okay. Who's the kid?" Sam called back.

"Do you have a knife?" Clementine called down the hole. Then, to Sam she said, "I'm Clementine."

"Yeah, here," Dean reached his switchblade as far as he could. Clem's hand was warm when it brushed his.

"How'd you get in here?" he heard Clementine ask.

"The spirit dragged me through the wall," Sam replied. "How did you get here?"

"I crawled through the—"

"And why the hell are you here, anyway, this is dangerous!" Sam's voice got closer. "Dean?"

"Like she said, her name's Clem. She insisted on coming. You in one piece?" Dean leaned down. He could see Sam silhouetted in the light of Clementine's flashlight.

"Little banged up, but yeah."

The door to the basement opened with a creak. "Clementine?" The man with an English accent called.

"That's how we can get Sam out! Move!" Sam was shoved away, and Clementine crawled back through the short tunnel. "Doctor! Doctor down here! We need the Tardis!" she ran up the stairs and had a hurried conference with the English man in the trench coat, then came back down, a satisfied expression on her face. "Don't worry, Sam, we're going to get you out!" She leaned happily against the steel plate and looked up at Dean with a smug expression.

"Gimmee that," Dean reached down at pulled the handgun out of her grip. A strange vworp sound filled the basement, and a strong breeze came from the tunnel.

"It's okay, Sam, that's the Doctor," Clementine called into the hole.

"Are you coming, Sam?" The Doctor's voice carried through the hole.

"Sam?" Dean called. The vworp returned, and Sam didn't respond.

Clementine looked up at Dean. "He probably landed outside. Doesn't like landing in basements. Too dingy. Come on!" She tugged on his sleeve and led him upstairs.

A dazed Sam was waiting by the Impala, pale and bloody. A batter blue box the size of a telephone booth was sitting on the side of the road nearby.

Dean stared at Sam a moment, then hugged his brother tightly.

"Are you all right?" the man asked Clementine.

"Just like old times. Only better, because this time everyone made it out," Clementine replied, a sad note in her voice.

"Old times?" Dean asked.

Clementine looked up at him with eyes far too old for her face. She looked as if she wanted to say something, but instead she swallowed and looked away.

"Come on, Clementine," the man said, holding out a hand to her.

Clementine looked down at her feet a moment, then handed Dean the flashlight he'd given her.

"Where are you going?" Dean asked as the two walked towards the blue box.

Clementine stopped and stared up at the Doctor.

"HEY! You think I'm going to let you to just walk away? What are you, hunters?" Dean demanded, leaving Sam.

"And what the hell is that thing, anyway?" Sam added.

"It's a Tardis, Time And Relative Dimension In Space," the man said. "I'm the Doctor, nice to meet you. You both know Clementine."

"Doctor...what, exactly?" Dean asked.

"Just the Doctor," the man replied.

"Are you hunters?" Dean asked again.

Clementine shook her head. "We're travelers. We travel all over. Sometimes we save people, sometimes we just look at cool stuff."

"The Doctor...I've read about you," Sam said.

"Really?" the Doctor asked, his eyebrows lifting up. "What have you read?"

Sam turned to include Dean. "He's some sort of creature. Not human. Either he can change his face or there's been more than one of them over the years."

Dean looked quickly at the Doctor, he stood with his feet shoulder-width apart, listening quietly. Clementine watched them with more obvious interest as Sam continued.

"He usual appears in times of need. He's credited as saving the world more than once."

"That's me, savior of the world, hallo!" the Doctor walked back and shook Dean's hand energetically. There was an obvious discomfort to his motion. "Come on, Clementine."

"You can change your face?" Clementine asked.

"Not at will," the Doctor replied, flicking the brim of her hat.

"I thought...I thought there weren't any more of you," Clementine asked, her brows pulled together in thought.

The Doctor looked away, and Dean recognized the expression that flashed across his face as grief. "There aren't. Not anymore. I'm the last."

Clementine nodded slowly. After a pause she said, "Do we have to leave? I want a cheeseburger."

"Girl after my own heart," Dean remarked.

The Doctor smiled down at Clementine. "She's a good girl. Cheeseburger, huh? I suppose that requires money?"

Dean bit back the wise-ass comment at the genuine confusion on the man's face. Something paternal cracked in him. "Why don't we take her out for a cheeseburger, and you can pick her up in a couple of hours."

"Clementine?" the Doctor crouched to look her in the eye.

Clementine looked up at both of them and nodded.

The Doctor pulled a cellphone out of his jacket pocket and handed it to Clementine. "You remember the number?"

Clementine nodded solemnly.

"Call me when you're ready to be picked up." The man straightened up and rubbed the top of her hat. He turned and disappeared into the blue box. The vworp sound filled the room, and the box faded from view.

"What the hell?" Dean asked.

"It's a space ship time machine," Clementine explained, as if this answer should pacify him.

"That's bigger on the inside," Sam added.

"It's what?" Dean turned.

"Bigger on the inside," Sam repeated.

"A lot bigger. You only saw the control room. There's also a library, a swimming pool, a wardrobe, and like a ton of bedrooms," Clementine said, her face glowing the way Dean's did when he talked about the Impala. "The best part is that it can go whenever or wherever we want! Well, most of the time." Clementine leaned in and dropped her voice. "The Doctor isn't a very good driver."

Dean nodded as though this all made sense and opened one of the back doors of the Impala.

An hour later she was sitting on the bed in their motel room, cleaning Dean's gun while he finished bandaging Sam's arm. The empty bags from their cheeseburgers were left haphazardly on the table.

"Why don't you take him to the hospital?" Clementine asked, neatly laying the pieces of the gun out on the towel.

"And say what, that we were attacked by a ghost?" Dean scowled at the bandage.

"Good point. You...still have them though, right? Hospitals?" Clementine looked up at him.

"Yeah. Why wouldn't we?" Sam turned to looked at her, his eyebrows pulled together.

"My world didn't have hospitals anymore, in the end." Her voice wasn't much smaller than she was.

"In the end?" Dean turned.

Clementine looked down at the gun and began to piece it back together. "The Doctor says your world might be dying."

"Might be?" Dean stood up and moved closer.

Clementine kept her eyes on her work. "The apocalypse. Every world has one, the Doctor says. My world's apocalypse was..." she trailed off and stared off at the curtained window. "My world isn't worth visiting. Not anymore." She quickly made eye contact with Sam then looked back down at the pieces that were assembling into a gun in her hands.

"You survived a freakin' apocalypse?" Dean asked.

Clementine shrugged her small shoulders. "I had help."

"Where are they now?" Sam asked more gently.

"Didn't make it out," Clementine answered. Her hands stilled for a moment. "Anyway, the Doctor says your world is on a precipice. Not even he knows if your world is going to collapse or not."

"Wait...he doesn't think the apocalypse in inevitable?" Dean sat next to her, for the first moment a glimmer of hope appearing in his mind's eye.

"Apocalypses are always inevitable. Every world has them. It's the when that's sometimes flexible." Clementine finished with the gun and set it down on the towel. "Or at least that's how the Doctor Explained it to me. He says your apocalypse has started. But it's not too late to stop it."

"How? How can we stop it?" Sam sat next to her.

Clementine scooted away from them both, clearly uncomfortable with the scrutiny. "I don't know."

"Sorry," Dean set a hand on Sam's shoulder to hold him back. "We don't mean to crowd you, we just..."

"Don't want your world to end? Can't blame you," Clementine hopped off the other side of the bed and stepped into the bathroom, leaving the door open. "It sucks. Trust me." She ran water in the sink and Dean heard her wash her hands.

She came back out with the phone in hand. "I'm sorry, but I can't help you."

Sam's voice was thick. "Just knowing there's a possibility helps."

Clementine looked up at him for a moment, then nodded. "Thank you for the cheeseburger."

"Thanks for saving my brother's dumb ass," Dean answered.

She held the phone up to her ear. "I'm ready, Doctor." Before she'd lowered the phone, the vworp sound appeared again. The blue box appeared, then faded, the girl gone with it.

Sam and Dean traded looks. With a sigh they both got up and prepared to move on.