Trapped in a forgotten world atop an enchanted mountain, Monsters have been confined to an endless darkness. Life on the CROWN is dangerous and hopeless, with many monsters turning to cruelty to stay sane. On Halloween night, Jackie accidentally stumbles into this terrifying realm. They're told the only way out is at the highest peak of the mountain. With that in mind, Jackie sets out to climb to the top with their best Friend, Flowey. Will they forge friendships with the battle-worn residents that call this Hell a home? Or will they succumb to the ruthless law of this land... "Kill or Be Killed?"