Sunken Journal from Bel, a Mystery of the Shrine of the Coral Tomb.
I've come across many strange and interesting items in my time, but none stranger and more interesting than the seashell earring. I found what I took to be a run-of-the-mill seashell in rockpool that turned out to be an earring. How odd, I mused out loud, as I inspected it more closely. The sound of my voice triggered the earring and I heard the song of the merfolk, telling me to meet them. Which I did. They explained everything to me, and my eyes were opened to the world of possibilities that awaited me, deep beneath the ocean waves.