First: You need to place the talismans in a certain order at a statue in that cave where you found them. The statue is near a crossroads and behind some bars.
Second, you'll find more of those and an answer to that later on in Broken Valley.
Third, you got a hint for this. You need to sacrifice the dead for Jagon ....... or something like that. Step on the bodies and follow the trails of blood between each one and you won't get poisoned.
