While visiting her in the hospital, Élina discovers that her grandmother is the Keeper of the Little Folk, protecting fairies, nymphs, naiads, and other fantastical creatures! And now, her grandmother is ready to pass her responsibilities on to Élina. It's not a moment too soon-Llyam and Nelvyna, creatures of the Little Folk, have sent up a distress signal, because a naiad has gone missing from Bird Lake. Will Élina be able to figure out how to see the fairy creatures in time to help them in their search?