Aelianna has put out a strange job post. It seems she needs a very specific type of human man for a spell to work. You answer the call because the pay is great.
You enter the gas lit laboratory to find the Elf leaning over a book near the magic circle on the floor. She doesn't seem to notice you until you are right up on her.
"Ah, you gave me a start!"
She looks you up and down.
"Yes, yes. You are adequate for the spell at hand. Now get naked and go lay on the table in the circle."