Amanda looked at Captain Marvel, all six foot 4 inches of manly, big muscled super hero. He was one of the most powerful men in the SHR, having been pulled into commission as an agent a long time ago. When Captain Marvel had flown in with Jr., he was amazed that this girl was able to shrug off 2 very strong men so easily. And when he had went to subdue her, he was a bit stunned at how big her muscles were. His right hand was still holding her wrist and his left arm was locked around her upper arm.

When the gun was being fired into her body her muscles weren’t actually shrinking, Amanda had simply relaxed her body, causing her muscles to recede naturally, or naturally for her body. The first gun had given her the ability to expand her muscles to immense proportions and then reduce them back down when she relaxed.

As this gun increased her strength, the same relaxed muscles slowly became harder and denser. And geometrically stronger. So strong in fact that her muscles were still pulling in the energy Agent Thompson had so generously blasted into her body. And unknown to him, the longer the gun had been fired, the stronger Amanda would become. By the time he released the trigger, Arnold estimated that her strength would now easily rival that of Captain Marvel.

Only his estimates were off. Way off. For Amanda still had her ability to flex her muscles into gigantic mounds of teen-age girl fury, multiplying her strength to unthinkable levels. And as the last of the super strength energy from the gun settled into her body, her muscles now held earth shaking, dominating strength and power.

As Agent Thompson looked down at the gun, he shot a nasty glance at Arnold. “What the hell did you do boy?”

Arnold simply blushed, unwilling to admit that he had the gun set to increase Amanda’s strength, even though he knew she could be able to snap him like a twig BEFORE he turned her into an Ultra Girl.

As Captain Marvel tightened his grip, he was dismayed that this girl’s arm had no give. None. It was as if her arm were made of solid steel and he had the strength of Billy Batson. Amanda narrowed her eyes and glared at her now would be captor. This was bad. Very bad. And to make matters even worse for Captain Marvel, Amanda hadn’t even flexed her muscles up yet. And as her glee at what she now figured had happened turned to anger toward her remaining captor, she started tensing those muscles. And the strength within her began to build.

“Well, it seems like Arnold couldn’t bare to see me grow weaker. And knowing him, he had it set on the maximum setting. Want to bet I’m strong enough to kick your ass?”

Before he could react, Amanda brought her arm up and flexed down on her bicep. Muscle fibers began to multiply as the imbued strength of gods began to consolidate into her waiting biceps. As those crystallizing muscles slowly expanded, Captain Marvel’s grip slipped as he now had no hope of containing the strength and might of this teen-age girl. And worse yet, she was only getting started. As the sinews surged to the surface and shapely muscle inflated, her bicep peak pumped forward several inches, jerking Captain Marvel’s arm back and up in response. Amanda smirked at the struggling hero.

“What’s the matter, you jack booted thug? Can’t hold on to my arm? Can’t contain my girlish strength? Well get ready, because I’ve barely started to flex down hard Captain. And when I do, you’re going to know what the term super strength REALLY means.”

As Agent Thompson fiddled with the dials, he reached out to grab Arnold who continued to back away. “Get back here you little traitor. Show me how to reverse this thing.”

Another agent was also closing in on Arnold and by now half the SHR was being called to the scene. Arnold looked at the gun and shook his head. What was he thinking? He knew he should have set the gun differently, but, but somehow he couldn’t. And as he glanced over at Amanda, he knew why. She was flexing up her muscles. Muscles he knew all too well could grow to Hulk like proportions, but with Wonder Woman curves. Muscles he longed to worship. And now she had the strength to rival any super hero. Even as two agents moved closer he started to build up an erection at the thought. For now he realized what was happening. A normal sized Amanda would have become as strong, if not stronger than Captain Marvel. But a mega muscled Amanda would put him to shame! His breath grew short. Just how strong was she really? And just how strong could she become?

Captain Marvel began to sweat as he struggled to maintain some control. At this point he hoped this young girl would tire and that the ray really had not made her as strong as she boasted, or as strong as he feared. But as Amanda continued to tense her fist and bring her forearm up, her muscles continued to build and her strength continued to grow. Captain Marvel swallowed as his left arm was pulled up further as he was completely helpless against her continued muscle growth. Her bicep was now over 30 inches around and had risen over half way up her forearm. The sleeve had already split and now hung between the crook between her growing bicep and her muscular shoulder.

Amanda was enjoying things now. The strength that had been pressed into her muscles was now felt throughout her body as every muscle group tingled with the sensation. The feeling of super strength and unstoppable power was raising the hair on the back of her neck and pressed her hot, bullet nipples out to tent the already overstressed jersey. Her boobs had transformed into pure muscle, the fatty tissue replaced with nothing but strength and hardness. And as she pulled her forearm up higher, even more strength was instilled into every muscle fiber throughout her body. The warmth down below built as she involuntarily shuddered, tensing all of her muscles and pulling forth even more strength to her now waiting muscles. The pleasure continued to build the more she flexed her muscles. Captain Marvel grunted as Amanda started to bear down. Her bicep expansion increased more rapidly and rose up furiously as the continued pleasure of the experience increased her strength. And as the strength increased so to did her pleasure. And the only way to continue the cycle was to flex her muscles. To flex her muscles bigger. As her bicep peak neared the top of her fist, Captain Marvel was being pulled off the ground, his feet dangling helplessly.

Amanda was now sweating and her entire body began to shudder. Pulling her head back Amanda brought her forearm down quickly and with one final orgasmic flex, pumped her bicep peak to the top of her head, ripping Captain Marvel’s grip away and sending him sprawling backward. Amanda stood there for a moment, grunting, squeezing her muscle for all it was worth, watching the peak shiver and pulse as every muscle fiber bristled across her watermelon sized bicep containing unthinkable strength. Her jersey started popping threads as she tensed all of her muscles in a fury of seemingly impossible muscle expansion and super strength, building up a physique to put the largest male bodybuilder to shame with the overwhelming muscle size, yet with enough curves to clearly indicate she was all woman.

Captain Marvel jumped up to confront this super teen just as the last of the pleasure subsided. As he approached her, Amanda turned and delivered a punch to his chest with the force of a nuclear explosion. His body hurtled backward, slamming though houses, cars and trees with horrible cracks and booms as he rocketed out of sight, smashing into a hill over a mile away.

With the immediate threat gone, Amanda looked back toward Arnold as the two agents now had him subdued, even as he struggled to break free. Fortunately, they hadn’t got him to adjust the gun just yet. With a determined look Amanda growled.

“You leave him alone!”

The agents both froze and Arnold smiled. Amanda may have been mad at him before. So mad in fact she had to restrain herself from snapping his neck. But now she saw him as her savior. The one who had transformed her into a muscle loaded super being. Someone who could actually take on the SHR. Rushing forward quickly, Amanda knocked the agents away like flies and handed the gun back to Arnold. Smiling at him for a moment, she leaned forward and gave him a peck on the cheek. His blood escaped from his brain and he nearly fell over.

“Well brainiac, you’ve really done it this time. You were SUPPOSED to give me normal strength. Why on earth did you do this? Did you really crank it up all the way?”

Arnold blushed as his heart pounded. “I, uh really don’t know. The thought of you being strong. It was, well I don’t know.”

Amanda sighed. “Well if we live though this we can discuss it further.”

Arnold smiled sheeplishly and looked at the gun and back at Amanda. They were quickly being outnumbered. Amanda was strong, but was she strong enough?

As they both stared at the gun and then back at each other, Amanda and Arnold pulled their attention to the noise around them. Several more super heroes had shown up, floating warily above them. Two more SHR cars and several police cars skidded along the street. Agent Thompson was back on his feet as he barked orders into his cell phone that was connected to not just the other agents but into ear buds in the various super heroes. And as heroes and agent pulled in slowly around Amanda and Arnold a final hero slowly flew in. Agent Thompson dropped his cell. What the hell was SHE doing here. Of all the SHR agents, she was always been the toughest to control. Wonder Woman. Shaking his head, he pulled the cell back up. His orders were clear. Get the gun, stop the girl. By any means necessary.