Kiela returns through the storm-battered forest to her cottage, where Caz tumbles out, relieved she survived and confessing he'd already drafted multiple eulogies in iambic pentameter. She tells him about Larran's rescue and prepares to check on damages, but Caz warns of a bigger problem inside.

In the cottage, Kiela finds the copper bathtub dragged into the main room, holding a wailing mermaid. On the hearth lies the merbaby Kiela had glimpsed before, his green body slashed with purple marks and skittering with lightning sparks. Caz explains the mother hauled herself up from the cove. Kiela recognizes storm sickness—the magical infant absorbed too much storm magic. She offers to fetch Ivor, but the mermaid grips her wrist and insists, in halting words, that Kiela herself must heal him with a spell, because she healed the trees.

Kiela and Caz race to the back room and unpack the third crate, locating a green-covered veterinary spellbook with a section on magic-infused creatures. The spell requires sap from a lightning-struck tree, spit, a feather, soil, and rare verisad leaves. Kiela rushes to gather bark from a lightning-struck pine she'd passed, a feather from the chicken, and garden soil, while Caz hunts for a substitution for verisad.

No substitution exists, but the cactus, increasingly alert and helpful, returns from outside with shiny verisad leaves stuck to its spines. Kiela mixes the paste, spreads it along the merbaby's spine, and reads the spell aloud. The concoction absorbs into his skin, the lightning sparks fade, and he uncurls. The mermaid leaps from the tub to embrace her child, who submerges and laughs, healed. Kiela has successfully cast a complex healing spell—an unmistakable act of true magic.