Sea Change follows Miranda Merchant (Rudd) a teen girl on a journey to reunite with her estranged mother Amelia (Dizzia), who lives on a seemingly idyllic island off the coast of New England. As Miranda settles into island life, she finds herself torn between TJ (Tracey), heir to one of the oldest Selkie families, and mysterious bad boy Leo (Maxon) who is part of the working class "townies." When Miranda learns about the Seawalkers, who, according to local legend, are half human and half sea creature, she begins to believe that they could be real. As she uncovers more about her family's past, Miranda makes a startling discovery about her own connections to the Seawalkers. Based on Aimee Friedman's YA novel Sea Change.