Lyla (Lucy Fry) and Nixie (Ivy Latimer) are said to have left to search for a new home for the pod.
New mermaids Ondina (Isabel Durant) and Mimmi (Allie Bertram) are introduced.
In one scene, new mermaid Mimmi (Allie Bertram) is looking through Rita's tinctures and ingredients. She says to Poseidon "Sea urchin spines, ambergris... do you know how powerful this is?" H2O: Just Add Water's episode Irresistible features a bottle of ambergris that makes the mermaids act crazy.