WARNING: The following contains major spoilers for The Sandman Universe/Locke & Key: Hell & Gone #1 by Joe Hill, Gabriel Rodriguez, Jay Fotos, and Shawn Lee, on sale now.

After what seems like an eternity of waiting, the epic crossover event between Locke & Key and the Sandman Universe has finally arrived. Now, one member of the Locke family is about to discover just how horrifying the landscapes of the beloved Vertigo series can be. Though it might not seem like anything could be much worse than what the Locke's have most recently been through, in the absence of its ruler, The Dreaming has become little more than a living nightmare.

Mary Locke has watched her father become depressed over the past 12 years. The hellish version of his son that he keeps summoning from the wellhouse hasn't done his already deteriorating condition any favors, and Mary is determined to fix things before her father dies of old age or a broken heart. After traveling to England for a visit with Roderick Burgess, she is able to trade one of the magical keys for an audience with Burgess' captive Morpheus.

The Lord of Dreams refuses to speak in the presence of his captor, but he does leave Mary with a silent clue to guide her on her journey. This leads Mary to Roderick's son, Alex, who gladly trades her a couple of Morpheus' trinkets he has in exchange for the Anywhere Key. She dons Dream's Helm and Ruby and waits to be whisked off to wherever comes next. Unfortunately, what comes next is worse than she could have possibly imagined.

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When Mary sits up, she finds herself inside the Dreaming, the realms that Morpheus has domain over and where all beings go to dream themselves. While Morpheus resides within the Dreaming, it is not only under his control completely, but none of his subjects nor himself may come to any harm there.

Of course, Morpheus has been locked in Burgess' basement for quite some time, and so the landscape has deteriorated in his absence. Mary first discovers a grave underneath her, one with a living occupant inside of it. She dutifully digs in the hopes of finding help, only to run in horror when she discovers the rotting occupant, Abel, with a gnawing rat where one of his eyes should be. In horror, Mary flees towards a home very much like her own, one occupied by Cain, the twisted caretaker of the House of Mystery. As his brother approaches, Cain loads a keyhole-shaped cannon with nothing other than giant keys before shredding his brother into a gruesome mess with a single shot.

Once more, Mary is left shocked and disgusted as she takes off for anywhere else. Finally, she realizes that she is in fact within a dream, and that she might hold some power over it with the items in her possession. With the Dream Ruby in hand, Mary clears the surrounding fog and beasts to reveal a far more friendly-looking landscape ahead. As picturesque as it seems, things don't necessarily get any better upon closer inspection.

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As Mary walks through the stone archways and rolling hills, she comes across further monsters in her way, though these are far more dissuaded by her borrowed items than those of her prior encounters. Spotting Dream's Castle, Mary ascends the winding stairs to the entrance, spotting a caged and impaled Lucien, the Dreaming's head librarian, along the way.

Morpheus' absence at the point in time where this story takes place has only lasted a little over a decade, but the damage done to the Dreaming in that time is more than palpable. Mary Locke truly has no idea what she has just gotten herself into, and there is so far no indication that she has any idea how to get out of it. Hopefully, she'll find out sooner than later, as she has only just begun to dive into this particular nightmare.

KEEP READING: Locke & Key Creators Explain the Sandman Crossover's Origin Story