In my story, one of my characters is sent into a cave by a modern-day shaman to get a certain ingredient for a healing potion. It needs to be something that isn't immediately available online for order. His wife is dying, so he isn't going to want to leave her side, but if it means saving her life, he will. I already have the scene made out where he is going into a cave to get the ingredient, what I'm having a hard time with is picking the ingredient he is getting. All the mushrooms I've read about in caves are readily available to order online. The snakes that live in caves aren't venomous, so they don't offer much help. Open for suggestions.