https://morguefile.com/creative/Koan
Your hero, or heroine, is on an underground cave expedition with a guide. Something happens.
It might be a monster, a murderer, or a natural disaster – that all depends on you.
The bottom line…they’re the last ones alive and they’re fighting for their lives.
What happens? Where are they?
You can find this Story Starter and many others in 101 Halloween Story Starters, Romance Writing Prompts to Spark Your Imagination*
Check it out here>>>>http://amzn.to/2dvTFe0
And if you want a print/pdf version of it, you can grab it here 101 Halloween Story Starters PDF Version