When I was a kid I saw Curse of the Black Widow. It was a TV movie, you can check it out here, http://www.imdb.com/title/tt0075900/. It stared Donna Mills and Patty Duke – awesome, right?!
Thinking about this movie inspired a story starter but your heroine doesn’t have to prey on men. It can be a bit more romantic, if you choose.
Your heroine is bitten by a spider. She starts to change. Strange things begin happening. What?
What happens because of the spider bite? Who does she meet and how do they interact?
You can also get more spooky Halloween themed story starters
101 Halloween Story Starters, Romance Writing Prompts to Spark Your Imagination at Amazon
And if you want a print/pdf version of it, you can grab it here 101 Halloween Story Starters PDF Version