J.D. Berry's "Sparrow Song" -- getting past the beginning?

Playing Game Hints
1

I’ve started playing “Sparrow’s Song,” and I’ve gone to basically all the locations that seem to be available from the beginning, talked to several NPCs about various topics, and picked up a couple of things… and I basically have no idea how to make any further progress. Is there something obvious to do?

I currently have a locket, a peace treaty, my stick, and some clothes. I’ve talked to Cordelia, Tilson, Arctos, and the beholder. I’m considering kissing Cordelia just to see if I can advance the plot (though I’m sure the game would refuse).

If anyone is aware of a walkthrough or better yet hints, that would be super peachy.

2

Aha!

SHOW TREATY TO TILSON (or cordelia, or maybe someone else)

(Although that seems to lead to some fencing with the topic system. Still, progress!)

3

OK, now I’m at the puzzle that every reviewer seems to have got stuck on.

How can I get past the nymph? It seems that there is a different solution for each item you have – I have the locket.

I understand that it involves something unobvious that must be done four times. (Have I mentioned that I hate puzzles sometimes?)