This was a fun quest. Well-done! But there were some issues I had with it:
Issue #1 (Feature Request)
I found the implementation of the summoning stones a little confusing. When the circle is approached, Dorn makes comment on the fact that some of the stones are missing and must be fetched.
However, fetching the stones results in no visual effect! You see the same three stones on the map regardless. It'd be more intuitive were it possible to place the stones down via a usable icon; progress would be clearer.
Issue #2 (Feature Request)
Related to the conversation that occurs above, there's an option to accuse "the witch" of deceiving you when you find the stones missing. However, by the time I entered this area I already had two of the stones, making the culprit for their disappearance quite clear; moreover, I didn't need three stones -- I needed one.
In the event that the player has already acquired some of the necessary stones, the dialogue ought to change to reflect this.
Issue #3 (Bug!)
Once all three stones were acquired, a sacrifice had to be made! Great.
I elected to resurrect and sacrifice the druid. The moment he was raised, I clicked to attack him (oops). He died, Dorn made comment on a successful sacrifice, and then... nothing. No summoning, no further progress. Presumably because my party was busy trying to kill a dead druid.
This needs resolving.
Issue #4 (Feature Request)
After encountering the above bug, I reloaded. I returned to the sacrifice area, and this time I moved Neera to the center of the circle to click on the druid. Naturally, she proceeded to scream about this being way uncool, and then died to fulfill the sacrifice.
This was not my intention. Some kind of confirmation would be lovely here.
Furthermore, it would seem more realistic here if the chosen sacrifice fought against the party (afterall, would you just calmly lay down and die?)