ZacisateenageboywhodecidestocamponMakoIsland, unawarethatthreemermaids, Sirena, NixieandLyla, whoareguardiansoftheisland, arewatchinghim.Thatnight, whenthefullmoonrises, theboycomesintocontactwiththemagicwateroftheMoonPool.Thefollowingmorning, Zacwakesupdiscoveringhehasbecomeamermanwithafish-liketai...