Long ago, there was a count who was out hunting one day when he encountered a beautiful woman in the forest near a babbling stream. The woman's name was Melusine, and he became quite taken with her. He asked her to return with him to his kingdom and become his bride, and Melusine only offered one condition in their marriage: she was to be left alone one day of every week. The count agreed, and they were married.
Time passed, and Melusine bore the count many children, but each child had genetic anomalies. One son had differently-colored eyes: one eye green, the other red. Another son had the tusks like a wild boar. The count questioned why this was so, and became deeply suspicious of his wife. Nevertheless, he still allowed her to have one day of the week free to do whatever it was she did in that time.
The count's suspicions grew. Did she have a secret lover? What was it that Melusine did during this time? Eventually, the count's curiosity grew too much to handle, and he waited for Melusine to sneak away one day into the castle's bathing chambers and stood behind the locked door. He peered into the keyhole to see his wife bathing and became astonished when he noticed the long, scaly tail of a fish peeking out of the water. She was no woman! She was a mermaid!
The count gasped in surprise, and Melusine overheard him and noticed he was spying on her. She let out a terrifying scream and then, sprouting wings, she flew away from the castle, never to be seen again.
However, there would still be the occasional maid who swore she saw the figure of a winged woman with a fish's tail cradling the youngest child of the countess Melusina.
So, what did you think of it? Kind of creepy, huh? This is only one such version of Melusina's tale. There are countless others!