On her 13th birthday, Graciela (Latine) falls from a bluff into the sea and drowns. When she awakens 100 years later, it is to the calming presence of Amina, her spirit guide in the underwater world. As a sea spirit, Graciela works as a glazier, creating sea glass from trash, whereas Amina aspires to become an Alma, a “ruler of the sea realm.” Graciela dreads losing her friend to the Almas, so when she unexpectedly intercepts the Almas’ invitation to Amina, she hides their note. Graciela’s story alternates with that of Jorge (Latine), a living boy who stumbles upon a harpoon with a driftwood grip that resembles a horrified face caught mid-scream. As it turns out, the harpoon belonged to an unscrupulous ancestor who attempted to lance sea spirits and harvest the pearls their teeth had become. Graciela’s, Jorge’s, and Amina’s paths intersect as Jorge, in a disintegrating dinghy, flings the harpoon into the sea to prevent it being used by his greedy parents. He and Graciela, with some help from Amina and the Almas, must recover the harpoon, properly destroy it, and return Jorge to the safety of land. Rich worldbuilding and a fairy-tale ambience make for a magical, fast-paced fantasy adventure.