They dove together into a pool of calm below a waterfall that should not have been there. The water folded around them and let them through into a narrow seam of sea lit with an unworldly phosphorescence. Roads of tide—actual ribbons of rippling water—arced like bridges between phantom isles. At the center, a small stone rose like a fist from the water; upon it sat a shell the color of storm glass and inside the shell a small shimmering heart carved of drift-wood and mother-of-pearl—the Heart of Tiderun.