Jenny left her house and went to school. Her class had a field trip today and she was glad to get out of class for the day. The field trip was to the aquarium and for some reason this filled her with dread. She shook it off as she got on the bus. The trip was long in the city's traffic and the longer the bus ride the more Jenny didn't feel right. They arrived at the aquarium and Jenny was glad to get out of the bus. The class was taken on a tour of the facility. All the water, all the fish made Jenny long for it and her body started to feel tight around her clothes. After several hours of feeling uncomfortable they left and Jenny was feeling glad and disappointed. Her body told her to return later.
Around midnight Jenny decided to sneak out of the house. In long pants and sweatshirt she managed to take a bus all the way to the aquarium. She saw it was locked but she was able to trip the lock. She proceded to the tank with no real predators all sorts of fish. She thought to herself "one swim and i'll be good." She stripped off her sweatshirt and bra exposing her C-cup breasts to the air and hardening the nipples. She then stripped of her shoes her sweatpants and her panties leaving her naked. She climbed the ladder and jumped in.
The water felt amazing and Jenny decided to swim about. She dove down in the water amazingly able to see in the water. As she swam she realized that she needed air and tried to swim up. She got up to the surface and went over to the ladder but a searing pain stopped her she felt around her body noticing her shoulder-length hair was much longer like it reached her knees and much brighter like a blonde color. She felt her face and saw her hands had webbing between her hands. She felt her chest and felt her chest was much bigger almost a g-cup and felt something covering them. She looked down and saw two clam shells covering them. Another bout of pain made her look down and see her feet had flattened and she could see her bones in her feet surrounded by a membrane. Looking further up she saw millions of bumps like fish scales covering her body up to her stomach. A third bout had her legs coming together and moving her bones to line up with her spine. In horror she saw her feet become a fin almost eight feet wide and her tail was about the same size. One last bout of pain knocked her out.