Serena Blue has heard stories of the Old Mermaids all of her life, and she's tired of them and her mother's eccentric life in Santa Fe. She struggles to find her own identity after her boyfriend Stephen beats her. Serena travels to Oregon with her mother and her grandmother where she meets Annie and Freeman who comb the beaches looking for signs of the Old Mermaids. Serena learns that her grandmother believes she was once a mermaid before Serena's grandfather forced her to marry him; now she longs to go back to the sea. When Serena discovers her grandmother was once in a mental institution after drowning her baby son, Serena is sure her grandmother is still crazy. Family secrets begin to unravel, and Serena isn't sure what is reality and what is delusion. When Stephen follows Serena to Oregon, she has to decide if she will embrace her true wild self or return to her old life. Can she choose herself over her boyfriend before it's too late?