You sit on the floor by the sobbing girl and wrap your arms around her to comfort her. You hold her as she cries, but eventually she calms down.
"Thank you" she says, having regained her composure. "But I'm afraid you've doomed yourself by coming here."
"What do you mean doomed? Who's mansion is this? Why are we trapped here?" Glancing at her bare breasts you add. "Why are you naked?"
"The mansion is owned by a mysterious man I have barely seen, but who I think may be a wizard. I wandered here one night months ago. The water seemed so inviting I went for a swim. But as I was swimming the moonlight shone through the skylight above and I turned into a mermaid."
You look up and can barely make out a skylight in the roof that you hadn't noticed before.
"I almost escaped once, but the moon rose as I made it out the front door of the mansion. I collapsed there, transforming again into a mermaid and was stranded by my tail. I saw the man come for me as I desperately tried to drag myself across the yard. Then I blacked out and woke up here again. I though I escaped earlier tonight, but became lost in the mansion and must have gotten turned around when I found you here."
Suddenly, the woman grasped your arms tightly and looked at your face with fear in her eyes.
"The moon must be rising - I feel the change beginning again!"
You looked down to the woman's legs and saw them beginning to change. Her toes were losing defintion and scales were starting to form on her legs.
"You said I'm doomed. What did you mean?"