AN: A big thank you to all the reviews, follows and favorites. Made my day! On with the story :)

***sn***

"Hello Dean."

Dean fought hard to keep a smile off his face. Yes, he had seen the wings that were nothing like Lucifer's, but a niggling voice in the back of his head was telling him it could be a trick. Sam shared his brother's wariness.

"How?" Dean queried.

"How?" Castiel sounded confused.

"How is it you, Cas? How do I know Lucifer isn't just yanking my chain?"

The look that crossed Cas' face was something akin to hurt, but it disappeared as fast as it had come.

" 'cause last time he pretended to be you he tortured Sam," Dean growled.

"Yes," replied Castiel, looking down. "I remember. I wasn't strong enough then. But I am now." His blue eyes locked on Dean's and held the hunter's gaze. Then he looked at Sam. "I'm sorry, Sam."

"The question stands, Cas," Dean repeated, but his stance was slightly more relaxed. Lucifer might be one hell of an actor, but as long as he had made the brothers believe he was Cas, both Winchesters had felt that something was off with "Cas". Then they found out the hard way just what it was. Now, however, they didn't get the slightly off vibe from Cas, so maybe it was really their friend this time. "How did you give Luci the slip?"

"Enochian spell," Cas provided. "When I was still recovering while you were hunting the nachzehrer, I came across a book on angel lore. There were many spells, most of them I knew. Some, I didn't. They are hardly ever used."

"Okay," Dean nodded, walking over to the table, half sitting on it. "What spell is this? How to get the devil out of you?"

"Dean," Sam hissed disapprovingly. "Let him explain without having your sarcasm as a side dish." Dean raised an eyebrow in surprise and then relented, gesturing for Cas to continue.

"This one hasn't ever been used before as far as I know. It was intended for cases in which two angels share one vessel and come to a disagreement."

"A disagreement?" Sam asked. "I always thought most vessels can barely host one angel, let alone two."

"That is correct. Usually the human body can't cope with an angel's grace for long. Some can't cope at all. Double possession only happened once, but that was before I was created. If the stronger angel represses the other, the weaker can use this spell which, with time, will transfer the other's grace to his own."

"So what... you're like stealing Luci's grace?" Dean frowned.

"In a way," Cas replied, matching Dean's frown. "It takes time. It took me weeks. And I had unexpected help. Lucifer is a powerful archangel after all."

Sam had perked up at Cas' mention of help. "Who helped you? And why?"

"Amara," Cas stated.

"Amara?" Dean gasped.

"She didn't know. She still doesn't." A rare smile tugged on Castiel's lips.

"But... how?" Sam was searching for words.

"Amara tortured Lucifer. I had been repeating the spell ever since I said Yes to Lucifer. I suppose him being an archangel made it take this long. When Crowley tried to make me take over I wasn't quite there yet. Then Amara tortured Lucifer and I could feel I had completed the process. Lucifer is weak now. I have him locked away. But I had to act some part to escape Amara's clutches."

"So, does that mean you got archangel supercharge now," asked Dean.

"No, Dean. I got more than normal archangel power. My grace didn't consume Lucifer's. They combined."

"That why your wings look like they had a power-up?" Dean sounded excited.

"I believe so, Dean," the angel replied.

"Sammy, maybe we can book angel time travel after all."

***sn***

Amara stared at the spot where Lucifer had been only minutes ago. She had tortured him, turned his grace against himself, in hope God, her brother, would care and show himself. And then, in the blink of an eye, Lucifer had disappeared. She had taken a breather, considering her next attempt, because obviously the archangel's screams had not phazed her brother enough to intervene. Now, she had wanted to consume his grace, like she did with human souls.

"How did Lucifer get away?" she thundered. "He was weak! He was powerless! Who helped him?"

Trembling with hardly contained rage, Amara paced up and down. Outside, the skies were darkening in reaction to her mood. She was too furious to care. Then she stopped in her tracks.

"My brother might not care about this particular archangel, even though he used to be his favorite. He did lock him away, like he did with me. But there are always the Winchesters."

A tiny smile appeared on her face and the mark of Cain started glowing faintly.

"Dean is off limits regarding torture," Amara pondered out loud, her smirk growing wider. "But there's always Sam."

***sn***

"It actually is quite easy," Dean tried to explain to Cas about the spell they found. "The spell, six hunters, the Colt and a steady hand with good aim," he grinned. "That's all."

Cas looked at his friend with a frown. "If it were that easy, why haven't you killed her yet? You know other hunters who would help out."

"First off," Dean started, "we don't have the Colt."

"And it can't be just any hunters," Sam added.

"How's that?" Castiel regarded Sam as he elaborated.

"The hunters have to share a blood line. And not just any blood line," Sam glanced at his brother.

"Has to be Cain's blood line, Cas," Dean jumped in. "And there are only two hunters of this line alive."

Cas nodded and walked over to the table, picking up the scroll with the Etruscan spell. After studying it for a moment, his eyes found both brothers.

"There's no way I can pull four souls from the pit, even with my enhanced powers. Especially since they don't really have a body to return to. But I could bring them here from the past."

The brothers shared a glance. "Actually, that's what we thought, too," Sam provided, trying not to sound too relieved.

"Will you be able to do four time jumps with your souped up grace?" Dean asked bluntly.

"I don't know, Dean. But I believe it's worth a try. Who do you need me to fetch?"

"Whoa, Cas, it's not that easy. We have to plan this carefully," Sam put up a hand to move a stray lock back in place.

"Yeah, but if we're doing that now, I need some coffee," Dean declared, starting towards the kitchen. "You coming?"

***sn***

"I don't like the idea of having to zap both of you along each time, as you put it, Dean. The human body is not made for excessive time jumping."

Castiel clearly wasn't happy with what the brothers had suggested. Dean put down his coffee mug, now empty, with a thud. "Can't be helped, Cas. They all think there's no such thing as angels. They're gonna be freaked enough as is so at least they should see a face they know."

"A face," Cas accentuated. "Meaning one of you is enough. Two time jumps each." At his stern tone Dean's eyebrows climbed up and he shrugged towards his brother.

"Fine with me," he then conceded and Sam nodded in agreement. "I'll get our parents, you fetch Henry and Samuel."

"Why do I...," Sam started, then frowned, looking crestfallen. "Shit."

"Sammy?" Dean's voice held a tone of alarm in it. "What's wrong?"

"It won't work, Dean. Our mother and Samuel, they're our blood relatives, but not Cain's."

"I... son of a bitch!" Dean stood with such force that his chair tipped over backwards and noisily clattered to the ground.

"So we're back to square one," Sam eyed his brother with concern. He knew Dean took it on himself, and only him, that Amara was let loose. And it bugged him to hell and back that he couldn't kill her.

"No, we aren't," Cas piped up. Instantly two sets of Winchester eyes were pinning him, daring him to explain. "Samuel and Mary Campbell might not be direct descendents of Cain, but they are his blood line."

"How?" Dean rasped.

"The Campbells are direct descendents of Able," Cas explained.

"And since Cain and Able were brothers," Sam smiled, picking up on it immediately, "they share the same blood line." Cas nodded.

"Dude," Dean squeaked, the cleared his throat. "Our families are going back to brothers?"

Sam rolled his eyes. "Millennia ago, Dean."

"The blood lines have been kept apart and it has been arranged for your parents to fall in love a long time ago," Cas brought up. "You were..."

"Meant to be born, yes. We know that part of the story, thank you very much." Dean looked at his brother. "Who do we get first?" Sam squinted his eyes, weighing up options.

"Dad."