The radio sparked to life. “She is at 200 feet already, we nee to hurry, agent Gregory.”

“I get it, I get it” Brooke said, while she prepared to drop down from the helicopter.

She checked her equipment one last time, then dropped down. Her black hair flowing freely in the air, while her blue eyes scanned the situation. She could see the body of the rampager a few hundred feet in front of her. She indeed was already pretty big, this could turn out to be more difficult than she thought.

She finally landed and took her parachute off. Then she relaxed and prepared herself for the next step. She took off her clothes. Her athletic body stood proud in the morning breeze, her defined muscles trembling in anticipation. The young futa looked down at her impressive member. “You stay calm until it’s your turn, all right? Then you can have all the fun you want.” Her male sex twitched in response.

Brooke smiled. It was time.

“Nate, do you copy?” She asked to her earpiece.

“I do, Brooke.”

“Please, activate the GSD.”

“GSD active, good luck agent.”

She tried to take a deep breath, but the first wave of pleasure hit her before she could fill her lungs. The sensation was so strong that she knelt down, barely keeping herself together. The device attached to her female sex, hidden under her cock, was viciously stimulating her. It was designed to bring the user to orgasm as fast as possible; a brutal but effective way to make F-agents grow, and quickly, when necessary.

Soon enough, she did reach her orgasm. The overwhelming pleasure crashed against her mind, she barely kept it at bay. Her muscles completely contracted in the effort of not giving in to the red lust. Her body started growing, reaching fifteen feet.

“F-Fuck, Nate. Could you go a little easier?”

“I’m sorry, Brooke, but we do not have time. If she grows another couple of times, she will do some real damage to this city.”

“Yeah, well, I could too if you’re not careful.”

“Oh, come on, big girl. I know you can do it.”

Brooke was about to give him a piece of her mind, but her thought got soon overpowered by another rush of pleasure. “S-Shit. This is going to be one of those days, isn’t it?” She said, gritting her teeth.

Again her orgasm came, quick and merciless. And again the walls of her mind threatened to collapse. But again she resisted. Her fingers clawing through the asphalt in the effort to remain sane. She reached thirty feet.

The rampager finally woke up again. The red lust oozing from her eyes. Almost immediately, she stood up and threw herself against another building, humping it with abandon. Concrete and glass falling down around her, while citizens gathered at her feet, humping and fucking her and each other.

The race was on.

The GSD picked up the pace, Brooke’s body was on fire, she could barely stay still. He breath was short. Her limbs were trembling.

Then another orgasm, and sixty feet were reached.

Then 120.

It took everything she learned in training and all of he experience to keep going at that pace. Her body was screaming to let go, to use the puny humans around her as toys, to fuck skyscrapers until they were dust under her. To use that pathetic city as a sex toy for her pleasure.

Another orgasm. She finally hit 240.

She took a deep breath, sweat fell down her forehead. Her dick was at full mast, painfully hard, with drips of pre-cum weighting as much as an adult human dripping down the head. The temptation to reach down and jack off was incredibly strong, but she had to resist.

She stood up and advanced towards the rampager, who was picking up the pace, the building groaned under the added stress. Just as she was about to tackle the giantess, the structure gave up and collapsed against Brooke. Untold tons of concrete and steel crashed against her, burying her completely.

With a roar, the futa freed herself from the pile of rubble, blood dripping from her head. Almost immediately, however, her fury died down; The rampager was growing again.

“Oh great.”

Brooke launched herself against the giantess, who was now nearing the 400 feet mark. The crowd, already decimated by the collapse, was now throwing itself under the growing body of their executioner, while she gently caressed her tits, lost in in an ocean of pleasure.

Brooke forced herself between the rampager’s legs. Her pussy was in front of her, red and dripping with arousal. The sheer power of her lust emanating from her sex was so strong, that the futa agent almost lost herself right then and there. It took all of her being to reach her objective and plunge her cock into her.

With her target being double her own size, she could be easily forced out of her or squeezed to death by her long and luscious legs. She had to get to her to orgasm as fast as she could, one last time to end the mission.

Fortunately, she got her just after her spurt, which left the giantess dazed by the sheer, overpowering sensation of her orgasm and growth. It took her a while to even realize she was being fucked, so lost was she in the red lust that was puppeteering her.

But when she did realize, she brought her hands on top of Brooke’s head and forced her against her midriff, while she closed her legs around her, giving the poor agent a full body hug, strong enough to break her ribs.

Brooke was barely able to move her hips, yet she kept going, pumping her erect member in and out of her pussy, while the moans of the giant girl reverberated through her own bones. Fortunately for her, it was working, she could feel her heart accelerating and her skin turning red. She was close.

And then it happened. The girl reached orgasm one last time, while Brooke screamed in pleasure and pain, as she let go, emptying her aching balls into her vagina. Spurt after spurt of thick cum flowed into her, so much that some spilled out, despite her being twice her own size.

The effect was almost immediate: Both giants began shrinking down. At first slowly, then more and more quickly, while the red lust released its victim from its sweet embrace.

Hailey woke up, naked and trembling in the middle of the road, surrounded by rubble, cum and blood. She looked around, terrorized and confused, until a tall and muscular figure approached her.

“You’re coming with me, cutie-pie.”