Jeff's length was finally retracting into its sheath and he looked around the destroyed bedroom. It could only hold two enormous drider due to its high ceiling, characteristic of the house's design.
He recalled the rules of the vials - that the transformation effects lasted no more than 24 hours. But rules were made to be broken, and he was not prepared to give this glorious body up now. Perhaps the creators of the vials even had some intention that those brave or foolish enough to use them may not fully comprehend the consequences. It was like making a deal with the devil.
"I did not drink from the vials, but I did have sex with you following your transformation. The...gift, can clearly be passed on through the sexual act."
"But that will mean that I shall become a weakling human again inside a single day. Too short a time to spend with you my King" Mary replied, her heavy breasts heaving with anguish. "I wish for your seed to take root within me, in this body."
"I myself will pass the gift back to you my love." Jeff told her in his gruff voice. "But we must use this day to spread the gift as far as we are able." Jeff considered models of disease and contagion that had been popularised in fiction, and knew that a critical mass of people with the gift would lead to the eventual elimination of humanity, to be replaced by a stronger, more aggressive, more worthy species, but a species which would leave the wastefulness of human conflict behind. The old causes of war - religion, race, want, would all be left behind, replaced by a super-intelligent, super-evolved race of Driders.
But every revolution needed a spark to start the fire.
"Mary?!" came a melodious voice from the hallway, followed by the clunk of the front door closing.
"Sophieeee" hissed Mary to Jeff as she heard the voice of her sister, placing her white. Skinned, clawed fingers on the arm of her mate. "You must make her one of usss!" Sophie's footsteps were on the stairs now and Mary scuttled up her web, tilting her abdomen, ready to cover her sister in her clinging silk.
The door handle to the bedroom turned, and Sophie entered. She was an attractive young woman, a little thicker set than her sister, with long, honey coloured hair, an hourglass figure, a pretty, heart-shaped face, and homely, C-cup breasts. She stared for a moment dumbstruck at the site which greeted her, too terrified in that moment to move. That gave Mary all the hesitation she needed to strike.
Mary's sticky threads shot out of the orifice above her monstrous vagina, a web of the constraining threads sticking her to the back of the door which slammed shut, in a star shape, her legs and arms outspread.
The two Driders slowly closed on Sophie, the thick ropes of the main web which covered most of the room creaked as they made their way across it with their many legs.
As they approached, Sophie looked at the face of the female and then the male, the terrible realisation hitting her. "Oh my God. Mary? Jeff? What have you done to yourselves?!"