It took me a long time thinking about it when I got it: "I wish that all of the naked women in this room was a mermaid that can be outside the water for a whole year without drying out or choking, but not notice the change."
The change was incredible too watch, but if they noticed the change, they probably fell like this(for each woman at least): Her rear end was gaining bulk, then she realized that her anus and vagina were being forced forward. At the same time her legs began to merge starting right from her crotch. As the merger slowly worked along her legs, she began to gain bulk in her hips and along her legs.
“What the hell is happening to me” she cried out. She screamed out for help but no one would hear her here. She was able to lean up again and was horrified to see that her legs had merged all the way to knees. “They are turning me into one of them” she thought. Tears streamed from her eyes as she began to sob uncontrollably. “My life, my body is gone” she cried. “Why is this happening to me, what did I do” she sobbed, as tears continued to flow. In 30 minutes her legs were now one long sheath. She gained some movement in the again, and found she could only move that as her bone structure allowed. Her legs still intact in the sheath, allowed her to bend the middle of her and push her a few feet in the sand. Her vagina and anus were now above each other in front.
Then more churning struck her whole body. She let out a cry and arched her back, as she fell backwards once again. She lost complete control of everything below the waist. She felt like her insides were being twisted around. Her lower half became a boneless mass than a new structure began to take shape. She could still move her arms and notice that her pelvis was gone, replaced with ribs, all the way down. Her skin began to become wet to the touch, especially below the waist.
Her sheath grew and tapered into a point. She regained movement in her lower half once again and found that her new “tail” was able to move, bend and twist in many ways. She leaned up and watched in terror as a tail fin developed from the end of her new body. “I’m turning into a fucking mermaid” she said. Tears still streaming she began to control her sobbing as she began to wonder what would happen to her next. Scales popped out of her lower half, first scattered then widespread. Her skin texture of her tail began to resemble that of a fish, turning blue gray and shimmering with scales. A large tailfin now fully grown was at the end of her tail.
But becuse they didn't notice the change, they didn't take this "becoming-a-mermaid" thing as something bad or even happening. Now what to do?