Chapter Text
The rhythmic rise and fall of her breathing was the only sound in the quiet bedroom. Helen Parr, the indomitable, Elastigirl, was deep in a super sleep, sprawled out on her stomach, blissfully unaware of the bizarre modification occurring just beneath the thick, silk sheets.
Unseen, yet undeniable, her gluteal muscles had undergone a silent, spontaneous, and precise expansion. An inexplicable five inches of added volume pushed outward, molding the sheet tautly over the new, generous curve.
A harsh mechanical BEEP BEEP BEEP tore her from the depths of slumber.
Helen slammed her hand onto the alarm clock, silencing the grating sound. She tried to roll over onto her back, but the movement felt... awkward. Instead of a smooth, easy shift she expected, her lower half seemed to catch on the mattress, sticking her in place for a half second too long.
She grunted, finally managing to flop onto her side, blinking heavily. Her eyes felt gritty, and the room was still a little blurry.
"Ugh," she muttered, dragging a hand through her messy hair. "Just five more minutes, please."
She pushed herself up to sit in the edge of the bed, planting her feet on the floor. The new angle and weight distribution made the simple act of sitting feel subtly off. Her hips felt wider, and the part of her anatomy making contact with the edge of the mattress was... firmer? Bigger?
She stretched, letting out a long, tired sigh. Her pajama bottoms felt noticeably snug across the rear when she walked toward the door, tighter than they were last night.
She paused, rubbing the sleep from her eyes. "Probably just woozy," she mumbled, shrugging the strange sensation away. "Maybe breakfast can help."
She shuffled out of the room, oblivious to the fact that her new proportion was already brushing against the doorframe as she passed through.
Helen shuffled into the kitchen, the scent of potential coffee already offering a hint of salvation. She moved with the practiced economy of a woman who needed fuel before she could effectively save the world.
While the toaster heated up, Helen reached for her favorite mug—a sturdy ceramic one she had rescued from a garage sale—and began the sacred ritual of coffee making. She bent over the counter to scoop grounds, and as she did, the silent, relentless expansion continued. Another inch of tissue spontaneously materialized, pushing her total growth to six inches.
There was no pain, no sensation—just a subtle, almost imperceptible shift in her center of gravity.
The toast popped with a cheerful CHING. Helen grabbed the two golden-brown slices, gave them a quick swipe of butter, and poured a generous cup of black coffee. She didn't notice the way her pajama pants strained slightly more as she walked, or the slight swish of fabric behind her as she moved past the dining chair.
Helen retreated to the living room, sinking into the plush sofa with a relieved sigh. She balanced the coffee and toast in a small napkin on her lap, lifted the remote, and flicked on the news.
The screen immediately showed a familiar cityscape backdrop and a dramatic headline: "Elastigirl Foils Chemical Master Plot: City Spared From Toxin Cloud!"
A chipper anchorwoman began: "In incredible news this morning, the city owes a debt of gratitude to the super known as Elastigirl. Last night, she successfully neutralized the villain Chemical Master at his abandoned shipyard hideout..."
Helen watched, taking a satisfied bite of toast. She stretched her legs out on the coffee table, settling in.
Then, she shifted slightly to get more comfortable. Her rear end, now significantly larger than she realized, felt jammed against the back cushions. She tried to scoot back further, but she was already hitting the hard edge of the sofa frame.
'That's weird.' She thought. 'This couch is huge.'
She adjusted again, this time realizing that her body was taking up an unusual amount of space on the cushion. She was sitting further forward than normal, and her entire posterior felt strangely compressed, like a giant, overstuffed pillow, wedged into a space too small for it.
She frowned slightly, distracted from the news broadcast. It wasn't painful, just extremely tight.
"Maybe I just need a new spot," she muttered, standing up abruptly.
As she rose, the thud of her coffee mug hitting the carpet was drowned out by a louder sound: the audible RIP of her pajama bottoms giving way under the sudden stress across her rear. The fabric tore right along the back seam.
Helen froze. She slowly looked down at her torn pajamas, then at the generous curve of her backside now straining against the remaining fabric. The wooziness vanished instantly, replaced by a jolt of wide awake alarm.
'Six inches,' No. 'This isn't just woozy."
Her butt wasn't just tight, it was massive, and it was suddenly very exposed.
The news anchor continued to praise her heroics on the screen, oblivious to the fabric casualty unfolding in the living room.
Helen stood stock-still in the middle of the living room, the ripped remnants of her favorite pajamas hanging precariously around her hips. The praise coming from the news anchor on the TV was a distant, irrelevant buzz. All her focus was centered on the catastrophe currently residing beside her.
She slowly reached a trembling hand behind her and cautiously touched the affected area. It was firm, perfectly smooth, and felt completely normal—just tremendously larger. It ballooned out, giving her a silhouette she hadn't seen since... well, never.
"Okay, Helen," she whispered her professional super voiced barely a croak. "Analysis. Immediate assessment."
She took a deep breath, grabbed the remaining pieces of fabric, and made a dash for the closest full length mirror, which thankfully was in the hall closet. She yanked the door open and spun around to face the reflection.
The sight was genuinely shocking. Her usually athletic, yet normal, proportions were drastically altered. The expansion was distributed evenly, creating a curve that was both high and exceptionally wide.
The gluteus now jutted out so significantly that it was impossible to stand flat against the wall.
If she tried to put her classic super suit on right now, the material wouldn't even clear her thighs. The expansion was too great.
The pajama seam had failed exactly where the fabric was stretched to its limit—a clean, linear tear that confirmed the growth was symmetrical and recent.
She pressed her hands firmly against the tissue, using her powers of tactical feedback.
The tissue stretched normally when she pulled on it, just like the rest of her body, but the sheer volume was staggering. She could stretch it horizontally across the mirror, but when she let go, it sprang back to its new, enormous size.
It didn't feel heavy, nor did it feel like it was filled with air. It felt like her regular muscle and tissue, just... multiplied.
When she flexed her muscles, the entire structure moved. She could contract it, but she couldn't shrink it. Her powers couldn't reverse whatever force was causing the change.
Helen stepped back, staring at her reflection with wide eyes.
"Six inches in a few hours," she calculated mentally. "No symptoms, no pain, just pure unexplained growth. This isn't a weight gain, this is a physically anomaly. It means I was either hit by a highly specific, delayed-reaction bio weapon, or I'm reacting to a completely unknown environmental factor."
Her professional alarm bells were ringing loudly now. This wasn't embarrassing; it was a security threat to herself and potentially everyone she knew. And if it kept growing...
She had to get out of the torn pajamas and into something that could accommodate the change, which was going to be a mission in itself.
Helen stared at the large unfamiliar rear staring back at her in the mirror.
Helen let out a frustrated huff, trying to pull a pair of her normal, reinforced super casual jeans up her thighs. They got stuck halfway up, refusing to even attempt to climb over her newly expanded backside.
"Absolutely not," she muttered, tossing them onto the growing pile of discarded, size inappropriate clothing.
Her power was about elasticity, but even she couldn't stretch denim fibers to accommodate this new volume without destroying the garment and possibly ripping her legs out of the equation.
She needed something with maximal stretch, minimal structure, and an enormous amount of tolerance. Something that could handle her elastic nature before this bizarre growth, and now, handle the growth itself.
She quickly discarded most of her standard wardrobe: suits, dresses, fitted pants, anything with a zipper. Her eyes fell upon the back corner of her closet—the storage area for her specialized, deep cover disguise gear and training clothes.
She pulled out a pair of her oldest, thickest black yoga pants—the ones designed for extreme flexibility and movement. They were a synthetic blend with incredible four way stretch, and they had always been slightly roomy.
Success: With a surprising amount of effort, she managed to pull them up. The fabric screamed a silent protest as it stretched to its absolute limit across her rear, becoming sheer and glossy back over the massive new curve. It fit, but it was clinging like a second skin, accentuating every inch of the expansion.
For the top, she grabbed the largest, baggiest, grey sweatshirt she owned. It hung loose over her shoulders and chest, but thankfully offered a necessary degree of coverage over the startling prominent rear view.
Helen turned back to the mirror, her eyes scanning her new appearance.
The yoga pants were doing their job, but they turned half her lower half into a visually striking anomaly. She looked like a slender, fit woman who had been surgically attached to an enormous, perfect sphere of muscle. The baggy sweatshirt helped distract the eye from the sheer width, but couldn't hide the incredible projection behind her.
"Well," she sighed, giving her backside a firm, self-conscious pat. It felt like hitting a large taut drum. "At least I'm decent. Now to figure out how to get off the grid and find whoever did this."
She moved toward the door, taking a final necessary precaution. She had to navigate carefully. The doorway she had clipped on the way out was a tight squeeze now.
Before she left the room, she bent over knees slightly, calculating her clearance. She needed to tilt her hips just so and edgeways to avoid getting permanently wedged in her own home. This was going to make running an investigation extremely difficult.