Sitting in the darkness of his room, Danny's mind began to go wild with the plethora of possibilities the strange app offered to him. There were so many thing he could do! He could notch his body back to his bronze age counterpart, remaining muscular and handsome as a roman warrior; devolve Marco and his goons into precambrian protoplasm, mess with that stupid PE teacher who gave him the scathing nickname of Noodle, or...
A sudden thought crossed his mind, as Sophie's smiling visage appeared on his thoughts. He could devolve Sophie into another Neanderthal like him!
Danny's heart raced at the idea. He could tweak Sophie's mind enough for her to claim him as her mate, so when she evolved back, there was a chance she might have a residual memory that recognized Danny as someone she loved. A dumb giggle escaped Danny's mouth, and he began toying with the mysterious phone again. His larger, apelike fingers mad the swiping and scrolling process a tad more difficult, but Danny was patient.
He chuckled with arousal as Sophie's cute, blonde mug appeared on screen.
SUBJECT: HARKER, SOPHIE ELIZABETH.
GENDER: FEMALE.
AGE: 19.
SPECIES: HOMO SAPIENS SAPIENS.
PERIOD: MODERN AGE.
DE-EVOLVE? Y/N
Then he scrolled down, noticing the Advanced settings. There were a bunch he didn't understood, so he decided to leave them alone and avoid risking devolving Sophie into a puddle of goo or a cockroach by mistake. Eventually, he found out an 'Immersion' tab that he began to toy with.
He was familiar with immersion in videogames, as most of his PC games had dozens of mods that improved the experience, and from looking at the options he thought many looked like something straight out of the Sims. After adding a few more inputs, a new popup screen appeared:
SUBJECT: HARKER, SOPHIE ELIZABETH.
GENDER: FEMALE.
AGE: 19.
SPECIES: HOMO SAPIENS SAPIENS.
PERIOD: MODERN AGE.
MENTAL OPTIONS: CUSTOM
SPECIFIC INDIVIDUAL SETTINGS:
-ESTRUS (Y)
-MATE (HORTON, DANIEL)
-CHANGE PERSONAL BACKGROUND FOR IMMERSION (Y)
-CHANGE LOCATION (N)
-CHANGE PERIOD (N)
-INCREASED NEEDS (Y)
DE-EVOLVE? Y/N
Then, Danny noticed something else. Right under the new options tab, there was a warning message written in bright, red letters: WARNING - CUSTOM SETTINGS ARE STILL IN BETA MODE, UNWANTED CHANGES OR BUGS HAMPERING USER EXPERIENCE MIGHT OCCUR. ATAVISMSOFT WILL NOT BE RESPONSIBLE FOR ANY NEGATIVE CONSEQUENCES BROUGHT BY USING EXPERIMENTAL SOFTWARE FEATURES.
Danny stopped, wondering what that meant. He could discard it like he always did when toying with his videogames or modifying his PC, but something in the message seemed so... Well, ominous. What if he screwed up and left Sophie and himself as two subhuman beasts forever? Then again... What was so bad about it, in any case? At least by living like dumb cavemen, he could be with Sophie and go away from his already shitty life.
To hell with it, Danny said.
He needed to see it.
With an unusual stealth for something his size and shape, Danny opened his room's window and scurried into the darkened backyard. A dog barked at the distance, but aside from that, the neighborhood seemed to be sleeping.
The hunched Neanderthal Man holding a phone in his right hand, lumbered under the dark, hiding behind hedges, trees, parked vehicles and anything else he could find. He crossed the three street distance between his and Sophie's home in a couple minutes, then climbed on top of the large oak that grew in a garden plot next to Sophie's home and sat down on a branch in front of Sophie's window.
Danny was incredibly excited, his heart pounding with anticipation and his cock fully erect, readying itself to mate with Sophie as soon as her transformed self emerged from the window.
Danny could wait no more. And he pressed the De-evolve! button.
Inside her bedroom, the sleeping form of Sophie Harker moved under her sheets, squirming as her body was sent back in time. Her slender, slightly toned frame bulked with muscle and fat, her features roughened up and blonde, rangy hair peppered every inch of her body as she reverted all the way back to a stone age human.
The devolving girl grunted in her sleep. Her usual dreams were replaced by images of her mate and herself, two primitive humans, hunting game in grassy plains and then butchering animals with crude stone tools. And even her dream self kept reverting, as her depiction descended even more in time and soon became something out of a horror movie.
In the physical world, Sophie's bedposts protested, creaking under as she went from a fair 140lbs to a staggering 300 composed of raw, corded muscle and thick fat. Sophie jerked, aroused by her dreams and a strong kick from her right feet ripped the top of a bedpost as if it were nothing. The Neanderthal woman in her dreams was fucking her mate, and Sophie's body reacted accordingly. Her large, leathery nipples grew painfully erect and her swollen pussy gushed juice and drenched her bed.
Deep, animalistic grunts filled the bedroom and Sophie finally woke up. Sitting on her bed, the devolved woman failed to recognize her surroundings and jumped up in fear. She was in a strange place and surrounded by things she didn't understood. Looking at her right, she saw light coming from outside and upon yanking away the courtains, saw her mate sitting on a tree branch, looking at her on the other side of the glass.
A crude grin split Sophie's features, and using her newfound primitive strength, broke the glass with a swipe of a large, meaty hand. The cavewoman grunted and leapt at the tree, hanging onto another branch and then climbing all the way to her mate.
"Sophie?" Danny said. For a brief moment, he thought the custom changes had left Sophie as a dumb Neanderthal, but then she spoke with a deep, cavernous voice.
"Sofi scared. Sofi think Dann left Sofi in scary place. Sofi happy Dann here." The devolved girl then purred and cuddled against him.
Danny was overjoyed.
His plan had worked and luckily, Sophie's mind would retain enough changes upon evolving back for her to do the same when she was back to normal.
Sophie and him cuddled in the dark for a while, and Danny decided to add a couple more hours to the timer just to enjoy the evening.