From her viewpoint across the street Amanda couldn’t believe how well her little test had worked out. With a 20% blast Melissa had grown just a little bit, but it seemed she really got a strong boost of power. Amanda was really shocked at Melissa’s last serve which blasted through the fence and broke the driver’s side window of an SUV parked on the opposite side of the street from where the tennis courts were located.

Amanda held the gun up. “My turn!” she said with a gleam in her eye.

“Let’s see. 20% kept Melissa about the same size, but added some serious strength. I want to look a lot bigger, so I should use 80% and see how big that gets me.” Amanda cranked the dial up not realizing that so much of Melissa’s power was hidden by her thin frame just waiting for a strong flex to bring it out.

Amanda turned the gun on herself and, heart racing, pulled the trigger. The blast of energy was orgasmic, causing Amanda to drop the gun and bring her to her knees. She let wave after wave of pleasure to wash over her noticing that as excited as she was her heart rate was slowing. With each passing moment she felt her power growing, she couldn’t believe how strong she felt. It was as though an ocean of energy was flooding into her body.

After a full four minutes had passed Amanda was able to regain her composure and get her feet under her once again. When Melissa had been shot she didn’t seem to react nearly as strongly. That extra power boost must have really made a difference. Amanda walked over to her closet which had a full length mirror on it.

She noticed that her body had changed, but not nearly as much as she had hoped. Her denim pants were tight over her leg muscles, but were still holding with no stretching. Her short-sleeved shirt was pulled taut over her expanded chest, shoulders and back, and her breasts had even grown a bit into lovely C cups, but over all her musculature was no bigger than a gymnast while she had been hoping to hit bodybuilder levels.

With a slight frown she brought her arms up and flexed her biceps. Much to her delight her arms erupted into enormous balls of strength as if a bomb had gone off inside of them. Within seconds each one had blasted beyond size ever attained by a human being before reaching 34” around and splitting her sleeves up to her shoulders. Amanda gazed in wonder at her massive arms. When she released her flex, however, she was saddened to see her arms deflate back to their only slightly muscular size.

Beginning to understand what was going on she flexed her arms once more watching with sheer delight as they regained their massive size. Flexing even harder she watched as they grew even further quickly surpassing the 40” mark. Shocked at just how big her arms were getting she relaxed her flex once more.

Amanda then brought her arms in front of her and flexed her arms and chest. Her pectorals surged forward quickly shredding her shirt leaving her topless. She examined her sinewy chest, a deep groove cut between each massive pec. Placing her hands on her hips she flexed her chest even larger forming a shelf of solid muscle that stuck out a full foot beyond her chin, obscuring her view of the remainder of her body. Were it not for the mirror she’d have to only guess at her marvelous size.

Doing her best to hold her chest and arms at their current size while spreading her expansion to her legs. Within seconds her jeans began to split along either side, giving way to the massive slabs of muscle that were growing up and down her legs.

Amanda inspected her glorious, god like, body from head to toe. She was now clad only in her underwear, her clothes having long since succumbed to the hundreds of pounds of muscle that had sprouted up on her body.

Amanda spent the next hour continuing to expand and relax her body, exploring just how big she could get. Throughout the entire time she was experimenting she never felt that she reached her full size. No matter how big she got she always felt there was more power in her reserves. Before long she discovered that if she concentrated she could hold her size without flexing, allowing her to strut around her room posing and admiring her body from various angles.

Hitting a double biceps pose she smiled and said, “This gun is the best thing to ever happen to me. I can change from my normal size to massive and back again with a mere thought. I’m like the Incredible Hulk only better. How should I exploit this gift?”