Carry on though those wayward sons, Supernatural Season 10 has come to a close by its latest finale “Brother’s Keeper,” wrapping up the infamous Mark of Cain arc and birthing a whole new evil on the globe. Find out who suffered a swing of Death’s scythe, and what major evil will plague the Winchesters next year by our Supernatural finale breakdown!

You’re warned of spoilers for tonight’s Supernatural Season 10 finale “Brother’s Keeper” from here on out, but where the Mark of Cain has afflicted Dean Winchester all season, its evil has greatly expanded to bring a new (or old) “Darkness” upon the world. The combined talents of Sam, Castiel, Crowley and even Rowena succeeded in lifting the mark from Dean’s arm, but in doing so, unleashed an ancient evil as old as the universe itself.

As revealed by a visiting Death (summoned by Dean with some delicious taquitos), the Mark of Cain actually acts as a seal for “The Darkness,” an ancient evil beaten back by God and his archangels before the very creation of the universe. Lucifer took on the burden before his fall, subsequently passing it to Cain, who last season transferred the deadly sigil to Dean.

As such, even Death himself could not simply remove the mark without unleashing its inherent evil, nor kill Dean outright, but rather aid in transferring it to another, or transport Dean somewhere he could no longer harm another soul. Guess which one Dean chose!

Of course, Sam being Sam, the younger Winchester refused to let go of his brother, something Death and Dean has well-anticipated. After summoning Sam to their deathly pow-wow, Dean and Death made clear that Sam would have to die in order to keep Dean isolated and the world at large safe. The brothers brawled all over the barroom floor, before Sam finally accepted his fate, and Death granted Dean his famous scythe to do the honors.

Sam produced pictures of their mother to remind Dean how to find his inherent goodness upon any eventual return, sparking just enough of the elder-brother’s humanity to overcome his bout with pragmatism, and choose an unexpected target. With one swing of the scythe, Dean plunged the blade into Death himself, turning the entity to dust. Somehow, that’ll probably come back to haunt us.

Everything was hunky-dory from then on out, right? Not so much. You see, Sam neglected to mention that he’d earlier tasked Castiel with helping Rowena complete a spell to remove the mark, in exchange for her freedom. Castiel even summoned Crowley for help obtaining the ingredients, none other the forbidden fruit itself, a piece of the destroyed golden calf, and something beloved of Rowena’s to destroy.

That last bit seemed a bit unusual, and while Crowley himself couldn’t qualify as something his mother felt particular affection for, he did manage to track down a young Polish boy Rowena had taking a shine to centuries earlier, and since granted immortality. Rowena nearly broke down at the sight of her former friend, but tearfully killed her dear Oscar to complete the spell and win her freedom.

One quick flash of light later, a beam shot into the sky and landed on Dean’s forearm, burning off the mark, and retreating to the aether. All seemed well enough for a few minutes, before Sam and Dean ventured outside, wherein the skies streaked with crackling red energy  that shot into the fields outside the bar. The red bolts quickly gave way to pillars of black smoke that shot out of the ground and formed a giant mass of Darkness in the nearby field, one that quickly expanded and encompassed the boys as they attempted to flee in the Impala.

Oh, and as for Rowena, Crowley and Castiel? Her end of the bargain fulfilled, Rowena ditched her chains and took the books to got out of dodge, but not before freezing Crowley in place with her newly-unencumbered magic, and setting a mind-controlled Cas to finish her son once and for all. Hey, cliffhangers gonna cliff.

Well, did the final episode of Supernatural Season 10 effectively cap off a landmark year, 200th episode and all? What form might “The Darkness” take, and what might Sam and Dean do to combat it, with Death now a pile of dust? Was anyone else getting Thor 2 vibes from “Brother’s Keeper”?

Stay tuned for the latest from Supernatural Seasons 10 and 11, as cast and creators dish on what’s to come for Sam and Dean!