
When Mimmi and Chris go on a date at the beach, Ondina goes to great lengths to protect her. Cam tries to lure more upscale customers to the cafe.
While Ondina teaches the little mermaids to walk on land, her fastest-learning student wanders off and soon runs into Chris and Karl on the beach.
Zac realizes a shell he found has magical powers, and he accidentally sends the mermaids back in time five years, where they meet his younger self.
After overhearing Ondina blaming her for Evie’s loss, Weilan runs off. Meanwhile, Mimmi and Ondina combine their powers to try to restore Evie.
On the eve of the full moon, Ondina and Mimmi defy Veridia’s orders. Evie becomes suspicious when she spots Zac and Weilan meeting in secret again.
Zac begs Weilan to teach him an Eastern spell few have mastered, which he hopes to use against the dragon. Joe encounters a water ball.
Evie’s moon ring lesson with Ondina takes an unexpected turn. At the marine park, Mimmi discovers the reason for a rescued dolphin’s distress.
Weilan comes up with the idea of using a Chinese puzzle box to trap the sea dragon. Cam panics when Carly suggests they take dance lessons.
When Evie tries using her new moon ring to magically finish her chores, things quickly get out of control. Joe makes an upsetting announcement.
Weilan casts a knowledge transference spell on Zac to help him pass a biology test. But more than just science facts transfer from her body to his!
When marine park workers are sent to investigate the reported sea monster, the mermaids must create a credible explanation to stop further inquiries.
Ondina is tasked with teaching the younger mermaids. A mermaid from China joins the pod. During a full moon ceremony, a terrifying beast emerges.
The chamber’s true purpose is revealed: to drain the magic from all mermaids. Zac risks his life to shut it down and restore the mermaids’ magic.
When Erik learns that the trident stone is the missing element needed to activate the merman chamber, Zac gives it to the mermaids for safekeeping.
When Evie comes down with a fever that causes the temperature in the room to soar, Carly suspects that her friend is keeping a secret from her.
At the marine park, Ondina and Mimmi get into trouble when a dolphin splashes them and a little girl sees them transform into mermaids.
Ondina doesn’t want to choose between Erik and the pod when the pod returns. To cheer her up, Erik decides to throw a party in the café.
On the night of the full moon, Zac and Ondina sneak away to Mako, and Ondina reveals her plan to destroy the chamber.
Mimmi takes a job at the marine park, where she meets Chris, a young man who is desperate to get into a dolphin training program.
A surprise birthday party is in the works for Evie, who accidentally shrinks herself and falls into an aquarium after trying on Mimmi’s mood ring.
When Sirena sees a video that shows a kayaker being lured by a mermaid’s song, she starts to follow David obsessively, and he falls under her spell.
When Erik dives down and touches one of the rock outcrops on Mako reef, he’s transported into a sphere of endless water with no way out.
Ondina sneaks Erik into the grotto to duplicate a pearl he gave her, but she accidentally turns him into a copy of Poseidon.
After Cam absorbs moon pool water, he discovers he has power over water, which gets him a place in the trials for the school swim team.