Enter the stream with Maggie, a young mayfly nymph. Having lost her home to changes in the current, Maggie is searching the stream for the richest of foods with which to nourish her brief egg-laying flight in the world of air. But the stream, with its ever-changing currents, seems a confusing array of possibilities through which she must find her path. Where are the richest of foods? How might she find them? And what are the qualities that makes one's forage truly rich?

As Maggie travels the stream, she meets other streamlings—some malevolent, some benign—who offer advice based on perspectives they've garnered from their own experiences within the stream. Through these meetings, from a midge who seeks to understand the stream by classifying the minute grains of the streambed to a water scorpion who tells Maggie her only value is as fish food, Maggie, unsure of herself, must define her own vision or risk missing the fulfillment that she seeks.