Holly lay awake in bed, unable to sleep with all the thoughts rolling over in her head. She heard the door to the outside open, knowing that whoever her sister had invited over had arrived, and that she would be distracted for a while. Holly knew that there was no better time to find the Amulet and try and fix things back to the way they were, or at the very least make sure that Taylor's "niceness" wasn't all an act meant to lure her into a false sense of security. As quietly as she could, Holly snuck out of her room and down the hall to her sister's, the sounds she was making cluing her in that Taylor wouldn't be interrupting her soon.
Holly surveyed her older sister's room, trying quickly to deduce where the Amulet would be hiding. It wasn't in any of her clothes drawers; she had searched their the day before. And she could probably rule out her desk too; it would be too easy for something that valuable to get lost there. As she looked around more and more, the realization quickly dawned on her that the best place to hide it would be under the mattress. Certainly no one would ever think to look there, or would someone else stumble upon it by accident. With vigor, Holly stuck her hand underneath the mattress, feeling around blindly for the telltale plastic bag the amulet would be in. She could feel a string, probably the actual necklace of the Amulet, which was just out of reach. As she stuck her hand as far as she could to grab the mattress, she managed to get ahold of it along with some fabric just underneath it. The electric zap she felt from the Amulet was surprising, but she managed to pull it closer to herself along with whatever it was on. She froze though as it dawned on her what she had just felt coming from the Amulet, and the fact that it was in open air.
On fabric.
As quickly as she could she pulled the Amulet and the article of clothing out with it, her face going ghostly white when she saw a pair of boy's boxer shorts. Grabbing the shorts and the Amulet, she rushed to the bathroom as quickly as she could, already feeling the tingling sensation coursing through her body. "Nonononono..." she repeated to herself quietly as she ran into the restroom and shut the door, nearly locking it in the process. "No this can't be happening. Stop you stupid Amulet stop..." No matter how much she willed it though, Holly still felt the tingling continue to course through her body, even after she set down the Amulet and boxers. The room seemed to shrink slightly as she could feel herself grow taller slowly. She heard a ripping sound as she continued to grow as her nightgown quickly grew too small for her growing frame. "No! I don't want to be a gross boy!" Holly nearly shouted, surprised that she didn't draw attention to herself. Looking in the mirror, she could only watch as her long hair grew darker and began to recede into her head, becoming a shorter buzz cut in short order. Her face became more masculine, looking more like her father than anything else, as tiny hairs covered her chin and upper lip. She felt a burning sensation in her throat and coughed a couple of times as her voice dropped an octave or do, acquiring a deep baritone register.
Another final rip saw the remnants of her clothes fall off her quickly growing body, leaving her totally nude. Her body spasmed several times, leaving hardening muscles in their wake. Holly was an emotional wreck as she saw this, seeing a light coating of hair covering her chest and abdomen and all over her legs. Still, part of her, a growing part of her psyche, felt the strength in this body and was curious about it if nothing else. She felt a churning sensation in her gut and watched in amazement as a small fleshy nub began to grow out of her vagina, a small sack quickly appearing beneath it. It continued to snake outward, becoming wider and larger while the sack also saw two balls appear in it as well, becoming nearly as large as overripe tangerines before they were finished. As the tingling stopped, Holly could only stare in wonder at the boy...the teenage boy that she had been transformed into. Her hands, large and unfamiliar in their own right, traced their way over her new body, her breathing becoming more panicked. She was shocked out of this stupor by unfamiliar sounds coming from downstairs, reminding her that she was not alone in this house. As quietly as she could, she snuck out of the bathroom and onto the landing the overlooked the living room.
She was instantly greeted by the sight of her sister buck naked riding up and down on the cock of her boyfriend, gasping in pleasure and crying out Jacob's name. Holly backed away quickly, so as not to be seen, but she...he couldn't take his eyes off the sight of his own sister's breasts bouncing up and down in the throes of orgasm. Blood immediately headed south, and Holly felt her own new organ grow with arousal. This was wrong, he told himself as he retreated to his bedroom, grabbing the shorts and Amulet as he did so. That was his sister. His fraternal twin sister his newly formed memories told him. He shouldn't be turned on by this. Behind his own bedroom door, he didn't notice the changes that had overcome it. He was more consumed with the raging hardon that he now had. Try as he might he couldn't shake the images out of his head. Maybe it was the influx of new hormones, but whatever the reason, his body seemed to respond on its own, and his hands instinctively went down to his new tool and began stroking it. His stroking grew faster and faster, before he felt a rush of energy into his cock and shot out a wad of white liquid from the end. A few more small spurts followed before it shrank back down to the admittedly impressive length it already was.
"Fuck," the newly christened male whispered, grabbing a nearby sock to clean himself off. "I'd better wait till morning...then we can sort this out." With his body still on Autopilot, he threw on the offending boxer shorts for lack of anything else to wear, and collapsed into bed, the Amulet lying on the ground where he left it.
The next morning...