Sold to creature hunters by her new foster family, Aida seizes the first chance at escape when stealing her new little sister, Keely. She knows nothing about her creature roots, but a caged life is too much to bear.

Rushing along the water's edge, she stumbles into their unlikely rescuers in the strangest way. The water holds secrets, but maybe some of them should've stayed buried...

Giving into her Merrow instincts might help, but will she sink or swim?