A Fish Out of Water

This is an idea I've had in my head for a long time, but it didn't turn out quite how I wanted, so I'll be redoing it. I finally got it on paper though! It's only taken me a year to getting around to doing it. So, anyway, if a mermaid was stranded or kidnapped from her home and ended up in a subway, what would she be begging for? Water, of course!