It is a familiar scene. If you close your eyes and you can picture it. A pretty woman walks into a dark alley.
She is in a big city. Their is steam rising from the sewer. It goes without saying that it is dark and the alley is dirty.
This scene has been shot a thousand times in movies, in tv shows, in music videos, and in books. It is cliche. One of the most common cliche scenes.
However, where it goes from here is up to you. You can go the cliche route. You can have her mugged, rescued by a handsome strangers, or one of the many variations.
Or you can try to come up with a completely different solution. Your main character could start dancing, break into a Broadway song, or turn out to be a magician, there are so many options.
The only thing that you have to do in this prompt is walk a young women into a dark alley and see what happens next. I have given you the beginning, but you can turn that start into anything you want.
Happy Writing!