Merge with them, binding them together!

The worm-like tendrils pushed deeper and deeper into Terra and Susan, terrifying them both. They felt strange pressures inside their bodies as the oily worms pressed into their deepest places. On the outside, they were firmly wrapped in the creatures, and pulled close together. Their hearts raced, even as they too were invaded.
Their bellies and limbs began to stretch, swell, and distort as the creatures took hold. Some of the worms, disturbingly, even began to crawl out of their flesh, as though they had passed through it like a spear. Terra managed a scream, Susan could only cough on it. A moment later, the worms were passing from mouth to mouth and pulling them in close. The same thing happened to their pussies, clit to clit, strange oils flowing between them. Then, in a wrenching jerk, their navels. Susan knew exactly what was happening to her, and would tell Terra in a frenzy if only she could speak. Terra only knew that she was being tormented everywhere at once. Her breasts became sore as tentacles probed from within, her nipples rubbing against the redhead's.
Some of the tendrils probed at the ports at the back of Terra's head, and pressed into the flesh of her skull. She felt strange sensations all over. She watched as several more pressed into the sinuses below the ears of the redheaded doctor. More moved into their ears, deafening them to all sounds other than a strange whistling. Still more moved over and behind their eyes, blinding them.
After that, the surrounding tendrils clasped tighter, until they both felt like they would be crushed. But something different happened...Terra and Susan felt an extraordinary warmth in their breasts as they began to merge with one another, chest first. There was no breath to scream with, only the worms. Their bodies were knit together at the cellular level, starting with their chests that were taking so much of the pressure.
After that, as muscle, bone and sinew stitched into place, their navel and bellies, then their groins and necks. Their shoulders and spines came together with a cracking sound, and their minds blurred as their white and grey matters melted into one. The creature they were becoming was far from human, but required humans to summon forth. Susan's eyes took their place right above and slightly between Terra's. The inhibitors in Terra's brain began to affect Susan as well. Their muscles swelled and toned, which helped considering their now enormous breasts. "They" became a "she", "we" became an "I".
The tendrils of the coffin became an integral part of her body, and a strange sort of clothing on top of that. After a short while, she discovered that she could extend and retract them, to great potential distances and with great speed, with no more than will. And most of all, through all these hazes of cluttered memories in her head, she wanted to fuck. Everyone. Now.

Antoinette observed the shuddering creature on video. So, this was what was meant to be unleashed on the enemy. Antoinette was not innocent, but she was not without a conscience, and that resolute attitude that had held her in the esteem of her equally guilty colleagues had recently broken. Susan was young, and not as guilty as the others. If all was well, she would simply be in prison, serving out her days like a good little girl. But this madness had gone too far.
Antoinette, for the first time in her entire career, was taking matters into her own hands. Susan was not the other candidate, the candidate was still in storage in the room. They had dug so far and gotten so close to this mythical hell... what are a few floors more for her?