It was the start of all time everywhere, God stood there smiling to himself before glancing left to right at his world. He was getting ready to create his 13th world since his sister was finally contained. Humanity was going to survive this time around, waving his hands over the empty space between the stars and the gasses took form of the planet we now call Earth.
Time went by as it should, demons and humans even angels going about as usual. 2003 happened, the Winchester boys coming about, God disappearing, demons raiding the world. It wasn't til the year of 2013 that the bothers found out about The Men of Letters and the Mark of Cain but what the brothers weren't prepared for was their now sense of danger.
Castiel had returned to Heaven for some information on the Mark of Cain but what he found instead was something called the Mark of Zin. Mentioned only as Cain's opposite then nothing else, there wasn't even any books talking about Zin's mark. It was almost strange that was just a few mentions about this new mark but literally just showing up as a thing and nothing more, unlike the Mark of Cain, in story, who passed it down from and where it is.
Castiel poured over every book that had anything close to both marks but there was more information, which was really little almost nothing on Cain but nothing on Zin, just that it is Cain's opposite. With the little he had Castiel returned back to the Winchester boys, telling them about the new mark. Confused and frustrated on all of this they put it on the plate but put it aside to deal with later.
The First Blade calling out to Dean as they kept running into walls of dead ends to get it off, their biggest threats were dead and Dean was getting worse, Sam and Cas worried to the point of getting hardly any sleep; for Sam at least. Sam tricked Dean once again to sneak out to talk to Cas about this new mark and finding a spell to get rid of Cain's mark. "This new mark raises a whole new book load of questions." Sam said as he leaned against his new stolen car, Cas standing there with a strained face at Sam. "Maybe its from the time the Mark of Cain was made, given the lack of information." Cas guessed as he shifted his head slightly.
It wasn't til Dean caught on to what Sam and Cas were up to that they found out any info on the mark of Zin. Cas got his grace back from Metatron and also acquired the info they needed on the Mark of Zin. Azurl and his wrongful imprisonment. The only other problem was to find the other mark, thinking it could help them with Cain's mark. But still no information on what it looked like or even if it was good to the Winchester's. Metatron had no real information on it or it's captive, just that the male was around when or before the arch angels came to be. That night broke with more dead ends and drunken sleep, Castiel however took a little trip back to Hell to speak with Crowley about Zin's mark and surprisingly he knew more than the God's squire.
"The mark of Zin was supposedly believed to be lost and about freedom." Crowley spoke as he poured himself a shot of his favorite scotch. "It was what the demons rumored to be a cast away from the time of Cain's cage was made, no one knows whats inside or even if what was put there is even alive anymore." "Is there a way to see into the cage?" Cas questioned. "Look in?" Crowley questioned Cas's question "You're the King of Hell shouldn't you be able to get into or see into a cage?" Crowley smirked "Now you're rubbing my ego. But I just might have a way to see what's inside, since you're so forth coming with the foreplay." Taking another sip before setting the glass down and snapped his fingers only to turn his head towards their new found surroundings. They stood on the ledge of a trench and not to far in the distance there was this box hanging just a bit over eye level. "This is as close as we can get, any closer we plunge into nothingness or worse." Cas squinted his eyes and moved his head to see each side of the box and it's chains. "I feel... A Angel? A Demon? Something feels... Like it wants to be left alone and wanting freedom at the same time. What is this?" Crowley watched Cas as he spoke, curious and surprised to hear the words Angel and Demon leave Cas's mouth. "Another Angel?! In my Hell!" "You say that like it's a surprise. I thought you knew all of what was and is in here." Cas turned to Crowley in his usual confused face. "Its more of somethings that have been here since the dawn of time I can just barely feel let alone know what's in each dark cage." Cas watched him for a moment longer before looking at the cage once more. Before anyone could think about freeing the creature in that cell they had to figure out what it was and find its mark and vessel. Returning back to Crowley's throne room Cas asked if any of the books and or documents mentioned anything on Zin's mark and Crowley told him that the most that was said is that the lore spoke of an angel-demon that came before the arch angels but had said it had died. Cas seemed lost in his thoughts as Crowley spoke, pulling a book out of a secret hiding spot in the walls and showed Cas this symbol on the front of it and explained that symbol repeated its self in the book but nothing on it or the Mark. The symbol seemed to be familiar to Cas and he placed his hand over it and felt what humans called Safe, at home if you will. Crowley watched him for a moment before asking Cas if everything was good. "Something about this mark... seems familiar... Heaven familiar." "Familiar?" "Something about it I've felt before." Cas was unsure on it all.
Cas went back to Heaven's library of everything to do with the angels and their marks, some of them had symbols ether God gave them or the humans gave them. There he found the mark that made him feel at ease. The name over the mark was named: Zestiel, it was a really old symbol that represented freedom, apparently the home of the mark of them with that last bit in their name like Castiel. That time had died out a long time ago for angels to have a emblem for each of them, some of them for one angel or a whole set of angels.
Looking up Zestiel, Cas found out that he was imprisoned just a little bit after God sealed up the Darkness. His 'Home' crest, Cas was even more confused but it made sense in a strange way. Reading more and getting into books and documents he shouldn't, Cas found that Zestiel was an angel-demon like what he felt in the cage. It was listed as Zestiel was rebelling against God and got his wings torn by God's hands. Imprisoned for the something like Lucifer, threat against humanity. Something about the report seemed wrong, tampered with. Cas couldn't put his finger on it but he felt with every fiber of his feathers that something was off.
Telling Sam and Dean about this new being he found but he tried to show that the being in the cage was good not horrible, but the words weren't with Castiel. Dean and Sam didn't really get the picture cause Cas wasn't really making sense, but once Sam got him to say it all in order, Sam was on board but Dean was already giving up on getting rid of the mark. Needless to say in the long run the Winchester's were being the Winchester's, wanting to take chances but at the same time they didn't. They didn't know what they were walking into and who could blame them.
Later that night, the sun was peaking out and Cas was reading a few things in the boy's bunker, that's when he noticed something on his vessels arm, an itch til he took off his trench coat and suit top, rolling up his sleeve to see the mark of Zin on him. Something clicked and Castiel Remembered on his Astral form there was this mark he didn't recognized but didn't really bother with it til now, how it was on his vessel was strange, scary strange.