When Saoirse and Ben's mother mysteriously disappears into the ocean, the two children go on an epic journey to find out the truth about her, and in the process, discover mystical secrets about both their mother and Saoirse herself. The film takes inspiration from the mythological Selkies of Irish folklore, who live as seals in the sea but become humans on land.

Princess Merida, an archer and self-reliant young woman, makes a decision which defies custom and brings chaos to her kingdom. To restore her kingdom, she must rely on her bravery and archery skills.