This article is about the third season of the H2O: Just Add Water series. To view the third season of Mako: Island of Secrets click here.

Season 3

It's nearly the end of the summer holidays and Cleo and Rikki are about to face their last year of high school without Emma, who has gone overseas with her family. Together with Lewis, they're confident they know everything there is to know about Mako Island, especially now that they no longer have to worry about the effect of the full moon. But when water attacks the girls on a full moon, they realize a new, potentially dangerous force is developing on the mysterious island, and a boy with freakish free-diving skills who stumbles upon the Moon Pool could hold the key to understanding the powerful energy...

Thankfully they find an ally in Bella, a new girl in town who reveals an equally surprising twist: she too is a mermaid with extraordinary super powers. Together, the new trio face phenomenal challenges as they discover the dark secrets of Mako Island and realize their destiny as mermaids.


Image Title Original Airdate Episode
S03E01.jpg The Awakening October 26, 2009 53 3.01
Cleo and Rikki face their final year of high school without Emma. They make a new friend in Bella and meet new boy Will – and encounter a strange new force on Mako Island that turns water against them.
S03E02.jpg Jungle Hunt October 27, 2009 54 3.02
Will seeks confirmation of his first experience on Mako Island. Bella volunteers to misdirect his search so he won't find the Moon Pool. The girls and Lewis discover the Moon Pool has changed.
S03E03.jpg Keep Your Enemies Close October 28, 2009 55 3.03
Cleo seeks a new job as an assistant dolphin trainer at the Marine Park. Rikki fires Nate's band from playing at the café until she and Bella reach an understanding.
S03E04.jpg Valentine's Day October 29, 2009 56 3.04
Cleo's forced to put Lewis' plans for romance on hold to restrain Kim's out of control love life. During this Don meets Samantha, a National Parks Manager and they start to date.
S03E05.jpg Big Ideas October 30, 2009 57 3.05
Zane concocts a dirt bike race to publicize the café. When Rikki discovers it's a scam she and Bella decide to teach him and Nate a lesson. Cleo and Lewis make a big discovery about mixing the waters in the Moon Pool.
S03E06.jpg Secrets & Lies November 2, 2009 58 3.06
Bella attempts to start a relationship with Will until she sees he's apparently got another girl. Lewis tests the magic Moon Pool water at school and attracts the attention of their Science teacher.
S03E07.jpg Happy Families November 3, 2009 59 3.07
A problematic family beach picnic leads Don to end his relationship with Samantha until Cleo encourages him to pursue it. Will's sister Sophie competes with Bella for a job at the café and sets her sights on Zane.
S03E08.jpg Kidnapped November 4, 2009 60 3.08
Rikki and Bella hide out at Cleo's to protect themselves from a full moon water attack. Bella's kidnapped by a water tentacle and taken to Mako Island. Lewis tries to keep Will away from the island so the girls can rescue her.
S03E09.jpg The Sorcerer's Apprentice November 5, 2009 61 3.09
Cleo defies Lewis' advice and experiments with the magic Moon Pool water. Using her powers, Rikki accidentally gets the water into Cleo's aquarium and all the girls have to rescue Cleo's fish Hector.
S03E10.jpg Revealed November 6, 2009 62 3.10
Bella's warned to back off from Will as he's on the trail of the girls' mermaid secrets. She gets too close to him and he finally discovers she's a mermaid.
S03E11.jpg Just a Girl at Heart January 18, 2010 63 3.11
Bella helps Will with his free-diving training but when she realizes he's more interested in her as a mermaid than a girl, she's hurt. Rikki and Cleo have to improvise when the café's first corporate function is actually a children's party.
S03E12.jpg Crime & Punishment January 19, 2010 64 3.12
Rikki receives counterfeit money at the café and is held captive by criminals on a boat. Bella and Cleo are forced to reveal the trio's secret to Will so they can rescue Rikki together.
S03E13.jpg To Have and To Hold Back January 20, 2010 65 3.13
Kim attempts to derail Don and Samantha's wedding. Lewis receives an opportunity to study in America. Cleo realizes she's got to let Lewis live his own life and let him go overseas.
S03E14.jpg Mermaid Magic February 22, 2010 66 3.14
Will pushes himself too far when Zane challenges him to prove his skills as a free-diver. The girls discover a unique crystal in the rock from the Moon Pool.
S03E15.jpg Power Play February 23, 2010 67 3.15
Sophie uses Bella's idea for a fund raising concert and presents it as her own to Rikki to gain publicity for the café. Cleo's caught in the crossfire with Kim when Samantha moves in and puts her stamp on the Sertori home.
S03E16.jpg The Dark Side February 24, 2010 68 3.16
Rikki is frustrated by the water attacks and goes to Mako Island on a full moon to confront the strange force in the Moon Pool. With Cleo and Bella delayed, Will pursues her and discovers she's been affected by the experience.
S03E17.jpg A Magnetic Attraction February 25, 2010 69 3.17
Cleo's introduced to Ryan, a young geophysicist who's working for Samantha. Rikki doesn't react well to Cleo consulting Ryan about the Mako rock and a fracture begins to appear in the trio.
S03E18.jpg Into the Light April 12, 2010 70 3.18
Rikki fears Ryan's explorations on Mako Island will uncover their secrets but Cleo and Bella discount her concern. She almost goes too far trying to stop Ryan from discovering the crystals in the Moon Pool.
S03E19.jpg Breakaway April 13, 2010 71 3.19
Will competes in the Free-Diving Championships but afterward chooses to break from the sport and shrug off Sophie's influence on his life. Rikki sees Sophie kissing Zane at the event and breaks off their relationship.
S03E20.jpg Queen for a Day April 13, 2010 72 3.20
Zane installs Sophie as head of staff at the café. Bella develops a sneezing allergy that also accidentally triggers her powers. Sophie seizes on the problem and looks to fire Bella and the band.
S03E21.jpg The Jewel Thief April 14, 2010 73 3.21
The girls discover the Mako crystals contain immense energy and need to mount a rescue mission when Zane jealously steals one in an effort to gain Rikki's attention.
S03E22.jpg Mako Masters April 14, 2010 74 3.22
The girls sit their final school exams and have to avoid a water attack in public when the full moon rises early. They confront the water force in the Moon Pool and are given a message about Mako Island.
S03E23.jpg Beach Party April 15, 2010 75 3.23
Bella's eager to ask Will to the end of year party until she sees him asking Rikki. A big misunderstanding occurs which prompts Will to express his true feelings for Bella. Sophie tries to get Zane to change the name of the café.
S03E24.jpg Too Close for Comfort April 15, 2010 76 3.24
Don gets a second job at the Marine Park on the Pirate ship and outshines Cleo, threatening the future of her Dolphin show. Bella and Will find difficulty trying to connect with each others' interests.
S03E25.jpg A Date With Destiny April 16, 2010 77 3.25
Cleo discovers a comet is causing fish to flee the waters around Mako Island. The girls find a way to restart the message in the Moon Pool and discover the comet will collide with earth. Sophie meets Ryan and with Zane's help they join forces to remove the crystals from the Moon Pool.
S03E26.jpg Graduation April 16, 2010 78 3.26
Sophie and Ryan damage the Moon Pool in their efforts to obtain the rare crystals. The girls improvise and use their own magic to prevent the impact of the comet and a planet wide catastrophe. Rikki, Cleo and Bella graduate with a surprise.
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