Letting Go Mako Mermaids : Season 4 Episode 13

Mimmi's visions of a mysterious mermaid lead her to the inescapable conclusion that she must be her and Zac's mother, Nerissa. Upon learning their mother is fabled Nerissa, Weilan recounts how their mother helped defend the Eastern pod from a rebel mermaid named Aurora but never returned after going to face her alone. Zac advises caution but Mimmi is determined to find out what happened to her. In her haste, Mimmi unknowingly summons the Water Dragon which pursues her only to vanish as just suddenly as it appeared. Meanwhile, Carly is frustrated by Cam pulling double duty as both her boyfriend and boss. Seeking clarity, she makes him declare what hat he is wearing at all times.