Inhalable hallucinogen that triggers flashbacks?

[igniocyanide]

I have this story in which the protagonist comes upon a cave; within a few minutes of entering it he starts to have flashbacks of memory. Later he discovers that other people have had the same experience there, only in varying intensity

Comments

[murstein]

You might try looking into the Oracle of Delphi. This National Geographic article discusses research published this decade. I'm not sure if ethylene is the ideal chemical for your plot, but it's at least one to consider.

[igniocyanide]

Hey, thanks! Will look into those links ^_^

[thenetwork]

Some kind of fungus spore would be your best bet. It's farfetched (I get the idea from an old episode of the X-Files), but fungi do grow in caves, and an unknown or little-know variant of one would work.