Helena returns with an experimental formula

You sit idly on the examining table, kicking your legs and growing increasingly bored. After several minutes a concealed speaker crackles to laugh and Dr. Philovibe speaks.

"Please remove your clothing test subj- ahhhh, young lady," the voice dissolves into static.

You strip without pretense, discarding your tanktop, bra, pyjama bottoms, and thong into a rumpled pile on the white tile floor. It feels cold on your bare feet so you hop back up on the examining table. At least the vinyl padding has already warmed to your body.

"Good," comes the voice over the speaker, "now, please position yourself on your hands and knees."

You assume the doggystyle position with your toned butt and the puffy lips of your bare pussy facing the one-way window. You wiggle your ass back and forth a bit to tease whoever is concealed behind the glass.

The door to the chamber opens and you look over to see Helena in all of her giant creepy blond woman glory.

Her boots click on the tiles as she wheels a medical cart over to the examining table. You notice she is wearing blue latex gloves. Helena looks over the cart and lifts what appears to be a giant syringe filled with fluorescent green

liquid. Thankfully, there is no needle tip at the end of the syringe, just a plastic nub about two inches long. She pushes the plunger on the syringe and a spray of green fluid squirts into the air. She nods with satisfaction and places it back on the cart.

"What are you going to do?"

"RELAX!" She barks in the opposite of a soothing tone.

Helena unscrews the top of a tub of some sort of medical cream and dips two fingers inside. She comes out with a greasy dollop of whatever it is on her gloved fingers. The giant blond strides around your naked body and stands behind you. She places one gloved hand on your butt and pulls apart your ass cheeks to expose your asshole to the cool air.

You look back over the mounds of your butt to ask her what she's doing when you feel something prodding your pink pucker. Helena coats your crack and your asshole in whatever greasy substance was on her fingers.

Without warning, but with some predictability, her fingers begin to work at your rear hole. She is not gentle, but she is careful not to hurt you as she works one and then two fingers inside you.

"Oooh," you moan at the sensation of the lubed fingers prodding and twisting inside your ass.

Just as suddenly as they were shoved inside you they are withdrawn. Helena walks back around to the cart and retrieves the giant syringe and something that looks an awful lot like a butt plug.

"This vill not hurt a bit," she promises grimly.

The plastic tip of the syringe fits easily and snugly up your bum.

"Hold still," Helena instructs.

You gasp as cold liquid floods your bowel. You can feel the syringe squirting the fluid deep into your ass. It's an odd but not entirely unpleasant sensation. By the time Helena has finished "injecting" you with the liquid you feel very full. She presses the tapered tip of the butt plug beneath the syringe and swaps the two cleanly. Your flooded ass is corked by the object.

"Very good, Joy," Dr. Philovibe says over the speaker.

Helena returns the emptied syringe to the medical cart and strips off her latex gloves.

"Now," Dr. Philovibe continues, "it will only take a few minutes for the formula to be absorbed into your bloodstream. Then we can see if my experiment has worked."

You feel warmth begin to radiate out from your ass. A strange heat soon suffuses your entire body. It's the pins-and-needles feeling of your foot falling asleep, but somehow inside your body.

You wonder what sort of insane formula Dr. Philovibe has just subjected you to.