Mickey Teasdale loves her quaint curiosity shop, where every item feels magical to her. But lately, the magic has dimmed; the shop feels cluttered, and even her stories seem as worn as the items she sells.

Everything changes when single dad Ren Montague walks in with his surly teen daughter, Ava. When Ava discovers a secret diary, she and Mickey believe it must have once belonged to a real-life mermaid! Ever sceptical, Ren tries to protect Ava from disappointment, but as they unravel the mystery together, something special happens…