Kim Possible's eyes fluttered open, waking up somewhere cold and feeble, something she had never seen before. She was still in her purple attire. She had just graduated from high school but does not remember anything about how she got here. In her confused state, she looked to her left and sat up, seeing a boy about her age in a green jacket and wearing a strange high-tech watch. He too woke up, with the same confusion clouding his mind.
Kim looked and said, "Hey, where are we?"
The boy replied, "I don't really know. I was going up against Vilgax when I fell unconscious and then... this."
"Whose Vilgax?" Kim asked, "I just graduated high school and now I am just here?"
The boy was unsure how to answer her question, but then he said, "Okay, let's start over. I'm Ben Tennyson."
"Kim Possible." She said, shaking hands and reaching for her pockets. "Wait, where's my Kimmunicator?"
Ben looks at his watch, the Omnitrix, scrolling through and finding only the original ten aliens.
They looked around the decrepit building, and Kim froze when she stumbled across the corpse of a Finger Maiden. She had been disgusted, especially after picking up a finger that she wasn't sure about. Ben joined in, pointing out a message this maiden left behind. It said, Though the path be broken and uncertain, claim your place as Elden Lord! A phrase stood out to them, Elden Lord? To them, it sounded silly, especially making references to elderly elves to be a lord of the realm. After this, they decided they needed to escape wherever they were.
Ben pushed open a large set of doors, leading them to the outside where they saw a cliff overlooking a castle and a giant Erdtree in the distance. They had to press on, so they left the Chapel of Anticipation and descended a set of steps toward a courtyard with a Marika Crucifix. Kim asked, "You know this person?" and Ben answered, "Nope." After entering this courtyard, an amalgamation of limbs and heads leaped and jumped into the center to their surprise. It was a Grafted Scion. Kim tells Ben to hang onto her as she reaches for her grappling hook, except like her Kimmunicator, her grappling hook was gone too. They needed a plan. When the Grafted Scion attacked, they split, and Ben pressed on his watch, transforming into Diamondhead, and forming a cage of crystals around the monstrosity. After the scion screams, the diamonds shatter. Ben was shocked and didn't know what to do. A lightbulb lit up as Ben hit the creature and Kim observed its movements.
Kim tells Ben to distract it while she tries to find opportunities to strike. While Ben remains in his Diamondhead form, forming weapons that also harm it, Kim throws herself and kicks the scion's head, breaking its stance. Now side by side, Ben turns into Heatblast, much to Kim's amazement. Together, they charged toward it and delivered the final blow to its head, killing the scion as it disappeared into particles.
The Grafted Scion also left behind its two ornamental swords and large golden shield that Ben picked up on the spot but saw Kim sitting in the center as he turned back. She had a tear come from her eye, realizing that they both killed something. "Did we just kill it?" she whimpered, hands on her face, "I know I defeat my foes, but never kill..." Ben approached her, saying he had been killing only when necessary in his alien forms. Kim, almost feeling like he had been in his shoes, curled herself tighter. Ben, feeling like he ran out of things to say, pushed onward to a ledge, collecting a bioluminescent and transparent nascent butterfly as he did. After crossing a wooden bridge to another edge overlooking Stormveil Castle, he tries to reach for more nascent butterflies, but a part of it collapses and he struggles to hold on.
As he tried reaching for his Omnitrix to turn into Stinkfly, a rock he was holding onto lost its strength, and right as he was about to plummet, Kim leaped in and grappled onto Ben. However, she was holding onto him on an already weakened part of the edge, and after it crumbled, Kim and Ben plummeted. As Ben yelled, "Stinkfly!" before pressing down on his watch, it only turned him into Wildmutt. As the fog got thicker, the two crashed into the water below and their bodies resurfaced, a dark introduction to the world they were in.
They floated for a while across the coast before washing ashore on Limgrave's southwestern coast. Water splashed as a woman in a cloak found them whilst riding her spectral steed, Torrent. Kim weakly regains her consciousness to see them. "Do you think they are the ones, Torrent?" she said, patting Torrent. "Well, you mustn't worry." She dismounts Torrent as she approaches them, saying as Kim loses consciousness, "One of their kind is sure to seek the Elden Ring. Even if it does violate the Golden Order..."
Kim woke up again, for real this time. Ben woke up too, in his human form.
Ben groaned and he said, "Where... where are we, Kim?"
"I don't know, but don't call me crazy when I say this, but..." Kim said, feeling hurt, "I think we died."
Ben reacted, "Died?! But, how are we alive?!"
"I... I don't know." Kim answered, with worry. "It looks like a beach, but not one I recognize."
They look around as the sun begins rising, seeing a wolf sleeping next to a Kaiden Sellsword, a mercenary from a faraway land sleeping by a fire. Sensing a bit of danger, Kim and Ben sneak past him and his wolf without waking them. Upon spotting a cave, they enter it and come across the Stranded Graveyard. They stumbled across a talisman depicting a golden ancient dragon, a Haligdrake Talisman which Kim decided to put in her pocket. After jumping down, they were about to approach the double doors when they saw a spirit sitting near a hole. Upon interacting with it, it only mouthed a few words, telling the "Tarnished" to relearn their battle arts.
Feeling that they already proved their worth fighting the Grafted Scion, they skipped the session and opened the doors together. They ventured through an empty room and ascended some stairs, where they found a tiny golden aura, known as the grace of the Erdtree. When Ben laid his hand on it, it sparked but it spooked him, making Kim chuckle. They then found it looked like a bonfire, A.K.A a place to rest.
Ben noticed a white transparent wall where he wanted to go and tried breaking it, without success. It was then he noticed an imp statue with two empty slots fitting for daggers. He asked if Kim had anything about that, and she denied having daggers. She then pointed to a central platform, where they ventured towards, and Kim accidentally stepped on a pressure plate, revealing it to be a lift. After the lift stopped, they came across another set of heavy doors that Ben pushed open, revealing Limgrave in its ruinous yet beautiful glory. Kim and Ben were awed when they exited, seeing a ruined bridge leading to the Divine Tower of Limgrave, even the Erdtree in the distance. They didn't know it, but they were in the Lands Between, unready for their new world.