Ariel, the sea king's daughter, has always been curious about life above the ocean's surface. Ignoring her father's warnings, the little mermaid spends her days collecting human treasures from shipwrecks and longing for new adventures. Then, her life changes forever when she rescues a human prince named Eric from a storm.

The sea witch, Ursula, offers Ariel a deal - a chance to be human. But Ursula has wicked plans of her own. With no voice and only three days, Ariel must build a connection with the prince strong enough to break Ursula's evil spell. But is the friendship between a mermaid and a prince enough to unite their two worlds?