Summary: SupernaturalXConstantine. S10 for Supernatural and 1x07 (Blessed are the Damned) for Constantine. Cas and Dean suddenly find themselves transported into John Constantine's world and work to understand the exorcist and the strange angels as well as solve the other-worldly case. However it seems like they're going to encounter some trouble first.

Recommended you watch at least one episode of Constantine but if not here's a useful little summary...

Constantine Summary: Based on the wildly popular comic book series "Hellblazer" from DC Comics, seasoned demon hunter and master of the occult John Constantine is armed with a ferocious knowledge of the dark arts and a wickedly naughty wit. He fights the good fight — or at least he did. With his soul already damned to hell, he's decided to abandon his campaign against evil until a series of events thrusts him back into the fray when an old friend's daughter becomes the target of supernatural forces.

Oh boy I watched this episode and found I had a particularly stubborn need to write a cross-over. I was so excited that I wrote the whole thing in one day. All of which I'll have out by the end of January. Please read and enjoy! If you're interested, I have another Supernatural story about what would happen if Castiel was in Season 1 on of Supernatural. Make sure to check it out!

I don't own either of these shows!

[PART ONE OF THREE]

PROLOGUE:

Castiel, Sam and Dean were in the bunker researching a strange chain of deaths in the Chandler, Arizona on an impressively boring Tuesday afternoon. Castiel narrowed his eyes at the wordy passage in the book he was reading through. He looked up at the Winchesters before straining again, to understand the dusty book.

"What do you have there, Cas?" Dean asked, looking up from a large book that had been less than helpful.

" I think I may have found something." Castiel admitted. That seemed to have piqued the boys attention and they walked around to see what the angel had found.

"Jeez, you can read that?" Sam squinted. The book was written in Spanish. Language wasn't a barrier for him but the state of the yellowed paper and the smudged and faded ink was.

Castiel squinted again. To most humans the text would have been nearly indiscernible. Luckily, he wasn't human.

"Yes, but the passage is in Spanish."

"Well then it's a good thing we recruited the angel," Dean said, "what does it say?"

"Uh, well. This passage is about the Chupacabra."

"Chupacabra? Those are only in Central and South America. I've never heard about one in the States before, not even as far south as Arizona. Are you sure, Cas?" Sam asked.

"The deaths were first livestock then humans being drained of their blood. It says here that Chupacabra's follow the same…mode of operations." Cas paused with a self-satisfied smile before continuing. "According to this—" A shiver rippled through Castiel's spine, causing him to jump out of his seat without warning, making his way to the far table.

"What is it, Cas?" Sam asked, both brothers hesitantly following the angel. Cas turned to face them, gripping a chair to hold himself up with a strained look on his face. Instantly, Sam and Dean were on high alert.

"Someone…someone's summoning me."

"Summoning you?"

"Yes, it's a relatively powerful summoning. I haven't felt one so strong for thousands of years. Ugh…" Castiel groaned grabbing his abdomen.

"What's happening?" The boys asked worriedly.

"I'm trying not to go…" Castiel's mouth was set in a straight line. "Sorry, it's not good."

"Shit!" Dean said, grabbing Castiel's shoulder a moment before the angel disappeared. Dean disappeared with him.

CHAPTER ONE:

John Constantine chanted over the summoning circle he had drawn and had begun chanting the spell. It was taking longer than he expected to summon Manny. He could feel Zed watching him as he continued to chant. "…please?" He finished to placate Zed who believed in the purity of angels. He opened his mouth to say something but before he did, and cloud of smoke and sparks appeared in the circle.

"Looks like we caught somethin'," John drawled. Zed stopped fanning herself in surprise. The smoke cleared quickly as a man in a familiar looking trench coat pulled himself up from where he had taken a knee. Another man, several feet out of the circle jumped to his feet and looked at him warily.

"Who the hell are you two?" John asked suspiciously. Zed looked confused. She had assumed that one of them was Manny.

"I could ask you the same thing. Why did you summon him?" Dean asked, pulling out the demon-killing knife.

"Whoa, there mate." John put his hands out him front of him, trying to appear unthreatening. "I have no bloody idea how you two blokes are here. I summoned…something else."

"No, you summoned an angel." Castiel said walking up to the man, who blinked in surprise.

"You're an angel?"

"Yes, I am." Castiel told him. Dean came to join him.

"Eh, no you're not." The exorcist said looking him over. "Why are you wearing…everything I am?" He asked, wondering how badly he had mucked up the spell.

Castiel looked at both of them, as if just noticing now. "These were the clothes my vessel. Unless you somehow influenced him, I assume this is a coincidence."

"Vessel? What do you mean, vessel?"

Zed joined them."Are you really an angel?"

"Yes."

"No, he's not. I've met angels." John glanced at his back quickly and in a mocking stage whisper said, "No wings."

"You cannot see angel wings. They are in a different plane of existence unless I chose to bring them here."

"Where are your golden eyes then?"

"Golden eyes?" Castiel asked. "Angel's eyes glow blue with their Grace, not gold."

"What the hell kind of angels have you met?" Dean had to ask.

John turned to him. "I suppose you're an angel too, eh?"

"No, I'm a hunter." Dean told him irritably. "I just saw my friend here being summoned and decided to hitch a ride. It's not everyday someone tries to get away with angel-napping."

"A hunter?" Zed and John asked together.

"A demon hunter. And if you know about the supernatural and you're still alive, I'd guess you're one too." Dean replied, tired of this guy's act.

"Mate you got it all wrong. I'm an exorcist." John pulled out a card and handed it over to the man. While he read it, John took another moment to look over the 'angel'. He didn't look a thing like Manny or anyone else he had seen. Furthermore, he wore a white shirt, lose tie (but unlike him, it was tied the wrong way) and his signature trench coat.

"Exorcist, Demonologist and Master of the Dark Arts? Long winded way of saying you're a hunter isn't it?" Dean asked him critically.

John ignored his question. "If he's an angel why are you with him? You said you're human."

"We were on a case involving a Chupacabra. It's a hound-like—" Castiel started to explain what he had just learned.

"We were working on a case. He's a hunter too." Dean interrupted.

John laughed. "With the angel's 'don't get involved' stick up their arse? Likely story." Dean was reminded of when he had just met Cas.

"Cas is smarter than the others. How did you summon him? Where are we?"

"I drew a summoning circle to catch the attention of a different angel I was trying to contact."

"Dean." Cas said sharply. "I didn't notice earlier, but this isn't the reality you're familiar with."

"What does that mean?"

"This is a very similar but alternate version of the world. Demons still exist but it seems others do not. And for some reason, it seems that angels here must be different as well."

"You mean like when Gabriel sent me and Sam into a alternate reality where we were in a TV show? Or where Sam and I weren't brothers?"

"Yes. Except I doubt different versions of you exist in this world at all."

"Oh, this is utter poppycock—"

"John, I'm going to attempt to summon this world's angels." Castiel said, causing everyone to look at him.

"Oi, I never told you my name." John said slowly.

"I am an Angel of the Lord. I know everyone's names. Dean, this is John Constantine, exorcist, and Zed Martin…psychic, it seems. Zed, John, this is Dean Winchester, a hunter and I am Castiel the angel. I'm also a hunter-in-training." He added with a smile as if it should be impressive.

An uncomfortable moment of silence passed before Castiel spoke again. "Well, I need to collect a few ingredients for the summoning. I assume ingredients are in the same places here as in our reality." A gentle wind and the sound of feathers signaled his disappearance.

Zed jumped back and looked at John. "Is he a real angel?"

John looked at the place where Castiel had just been with a look of shock on his face. "Yeah, love. Suppose he is."