Jason and Brett round up their friends to help rescue Charlie, but Jason must also tell them the truth about Neri. Dianne destroys all of her research on Neri after Commander Lucas tells her that he will have to file a report on Neri. The kids infiltrate the UBRI command post and are able to release the net and free Charlie. A blood test done on Neri indicates that she is not human. Dianne convinces Commander Lucas not to file his report. Leaving with Charlie on his annual migration, Neri tells her friends to watch for her return.

New monitoring equipment allows Dianne and Winston to hear Neri's communications with Charlie but when the tag on Charlie stops working Dianne must go out and replace it. Using the songs of Charlie and Neri, Dianne and Winston are able to attract Charlie to their location. Dianne runs out of oxygen while diving but is rescued by Neri who is forced to reveal herself to Dianne and Winston in the process. When Dianne's research is faced with being shut down, Neri replaces the lost transmitter on Charlie enabling her research to continue.

Asleep on her island late at night, Neri has a vision of her mother, she tells Neri that it is ""her time"" but Neri admits that she is afraid of what is to come. On the Ocean Planet, Shersheba is taken prisoner by Garron, on Malakat's order, upon arriving. She tells Garron that she has brought the cure to the virus—but will only release it if she is recognized as their leader. Neri stops at ORCA to discuss with the Bates family her plans to go to the pyramid. Neri asks Helen, who has been in contact with the underwater pyramid, to ask it to allow her to enter the pyramid undetected. Through Helen, the pyramid directs Neri to the ""cave of light"" in the outback. In the underwater pyramid, Malakat orders the pyramid to destroy ORCA, but soon after Neri and Jason arrive and start the process to destroy the pyramid. Just as they are about to finish, Shalamorn enters the central chamber and retakes control of her pyramid.

Jason takes Neri and Mera swimming off the ORCA platform. Mick finds out and heads out on a jetski, he falls off and must be rescued by the girls. Neri helps Mick with his reading, he in turn joins the others in keeping Neri and Mera a secret. Forsythe tries to get access to Dianne's research and cripples HELEN in the process, in the confusion Lyselle sees Mera in the coridor and reports back to Dr. Hellegren that Neri and Mera are on ORCA. Winston, receiving strange signals from Neri's island, goes to investigate and meets two strangers, but back on ORCA he says his trip was uneventfull.

Prior to leaving on the final survey mission, Dianne learns Commander Byrne has assigned Froggy, Zoe, Joanne, Rocky and Kimberly to her crew. Forsyth hides a transmitter on the boat to allow UBRI to follow it. UBRI divers are dispatched to apprehend Neri and Mera and in their struggle with the UBRI divers, Neri and Mera are caught by the boat's cameras for all to see, revealing their existence to everybody on board. Responding to Mera's call for help, Charlie intervenes allowing the girls to escape, it's the first time Mera has been able to talk to Charlie. After being told about Neri and her sister, the kids all agree to keep the secret, except for Mick who just says that he'll ""think about it.""

Neri leaves ORCA intending to save Mera and Charlie by giving herself up to UBRI. Brett chases after her, gets into an accident with a UBRI boat and is saved by Neri. Sam destroys his remaining records of the titanium deposit. Winston continues to secretly meet with the two strangers. Unable to bring the girls back to the island, Winston takes the two strangers to ORCA where they tell Neri and Mera that they have come to take them back to the Ocean Planet, their home. Vanessa helps Mick with his reading and defends him when Commander Byrne accuses him of slacking off.

Neri and Mera make the decision to return to the Ocean Planet and convince Diane that her research must continue. Froggy fixes HELEN, with a little help from Damien. Commander Byrne has Forsythe arrested when HELEN identifies him as the sabateur. The kids take care of Liselle, keeping her from contacting UBRI. Neri and Mera are taken back to the island, with Winston, Mick and Zoe acting as decoys to keep UBRI away. Final goodbyes are said as the girls board the spacecraft for home but after the ship leaves, one person has stayed behind. Neri says she must stay to ""finish father's work.""

Brett and Jason are out testing a new diving suit when Jason encounters a strange bright light while under water, the pair quickly leave and head off to see Neri. Back on ORCA, Winston is puzzled by a magnetic anomaly on his scans of the ocean floor, even more strange is that the anomaly is in the shape of a perfect square. Dianne announces that she is going to pursue the vacant position of ORCA Commander. Jason matches the location of Winston's magnetic anomaly to where he saw the strange lights, Neri is also intrigued by the region prompting a closer investigation of the region. Neri swims out to the sight with Jason and Winston following in the minifin, ORCA's new underwater submarine. What they find surprises everyone—a huge underwater pyramid. Meanwhile, at Praxis headquarters (Preventative Response And eXtraterritorial Intelligence Service), agents Jake Shelby and Elly Hauser are dispatched to Egypt where reports suggest signals from outerspace are being received.

As the kids are preparing for their shore leave to Port Jackson, Neri makes a surprise visit that forces Jason and Brett to take her with them. Damien invites Neri to see a movie but the experience frightens her and she runs off. On her own, Neri meets a young boy and helps him retrieve a stolen bracelet. Returning to ORCA, Jason and Lee find themselves alone but Commander Lucas' arrival makes for an awkward moment. Neri asks Brett what kissing is like and when he suggests she try it, she does—with Damien. Dianne and Winston come to the conclusion that Charlie is actually communicating with the small animal that accompanies him (Neri) but Dianne is not happy by Jason's lack of interest in the success of her research.

Dianne asks Neri to help with her research on whales, Dianne is especially curious as to how Neri is able to communicate with Charlie. Arrangements are made for Neri to stay on ORCA but as Dianne's work with Neri continues, Jason accuses his mother of ""monstering"" Neri when all Neri wants is to be a part of their family. Brett, Froggy, and Zoe chase after the spy who has been steeling Dianne's whale recordings.

Jason agrees to show Neri his and Jason's home on ORCA. After steeling one of Vanessa's uniforms and obtaining a fake ID from Froggy, Brett begins a long-winded tour of ORCA that he hopes will bore Neri into making her visit a short one. Neri however is quickly captivated by ORCA—just as Damien seems to be with her. Getting separated from Jason and Brett, Neri wanders into Dianne's lab where she encounters both Dianne and Commander Lucas. Meanwhile Vanessa discovers that one of her uniforms is missing and has an idea of just who is wearing it. Fortunately Jason and Brett are able to get Neri away from an insistent Vanessa and off of ORCA before any more trouble arises.

Neri returns to help Dianne with her oceanographic survey leaving Mera alone on the island to face a UBRI search party that has come to the island looking for them. Mick catches a glimpse of Neri and Mera on a monitor but everyone tries to make him think that he is just seeing things. He persists in his claim of having seen two girls but only Liselle, who is working as an UBRI spy, takes any interest. His story eventually gets back to UBRI where Dr. Hellegren plans to step up his search for the girls. When Dianne learns that Sam has been keeping his discovery of the titanium deposit a secret with hopes of cashing in on the discovery, Dianne asks him not to pursue it.

Neri makes her first visit to ORCA since her return, and tells her friends that she wants to discover who ""her people"" were. Jason, Brett and Neri go to her island to look for clues to her identity. Brett gives Neri the pendant he found in the flower, and Neri tells him it was her fathers and is a map of the island. Following clues found on the island, a large object is discovered under the island–from what they have learned so far, Jason suspects it to be a spacecraft. Mick locks Rocky in the recompression chamber.

After locating an underwater entrance to the spaceship, Neri and Jason enter the craft where they find some of her father's belongings. Taking the objects back to ORCA, one displays a holographic message from Neri's father that reveals how her people came to Earth–and that she has a sister somewhere on Earth. Kimberly challenges Mick to a race, but when she beats him, he refuses to pay up. Commander Byrne shows Dianne the top secret plans for the construction of ORCA City, she wants Dianne to do the oceanographic surveys. 1998 AWGIE Award Nominee: CHILDRENS: Screen Original (Ocean Girl Ep 16 - Jenny Sharpe

The search for Neri's sister Mera is underway. Mick asks Froggy to use his computer to change his grades but Froggy won't do it. Commander Byrne isn't pleased with her son's grades but Mick once again charms his way out of trouble. Rocky fixes up an old boat so Jason can leave ORCA as he pleases. Helping Winston with a survey, Joanne falls overboard. She is rescued by Neri, but to keep her a secret, Joanne is lead to believe that it was Winston who saved her. Dianne and Winston discover that Neri's presence enhances their scans of the seafloor. Dr. Hellegren discovers Neri is the creature that accompanies Charlie. An old newspaper article leads Jason and the others to the man who found Mera.

Mera is having a difficult time adjusting to living on the island and Neri leaves her alone while she goes to help with the survey again. Mick gets Froggy to use HELEN to spy on Vanessa's counselling session. The kids on ORCA throw a surprise birthday party for Vanessa but Mick's practical joke results in a dangerous chemical spill and fire. Jason and Brett lead a successful rescue through the air ducts. In the aftermath, it is revealed that Mick has a reading disability. Commander Byrne assigns Mick to Dianne's survey crew. Jason is not happy about his mother's developing relationship with Sam. Dr. Hellegren connects Mera's escape to ORCA.

Brett's birthday party proves to be a big hit with his friends but Brett is disappointed when he doesn't receive a gift from his father (his parents are divorced). Following a heated argument between Dianne and Commander Lucas over the acquisition of new equipment for Dianne's research, Winston suggests that they should make an effort to be nicer to one another. Talking with Froggy and Zoe about divorce and stepparents, Brett gets the idea that there may be a relationship at work between his mother and Commander Lucas, especially when he sees how nice they are being to each other of late. Brett's belief seems to be validated when he finds himself being given a private tour of the bridge by Commander Lucas, during which he decides to casually mentions some unsettling details about his mother hoping to disinterest the Commander. After saving Jason from a shark while swimming near her island, Neri tells Jason her life story—that which she remembers.

The spy takes the stolen whale recordings back to Dr. Hellegren at UBRI—Hellegren wants to be the first person to communicate with whales. Dianne's tests on Neri reveal a remarkable telepathic ability. Dr. Hellegren uses the stolen recordings to lure Charlie into an isolated bay bounded by an electrified net. Dianne readies Neri for her first dance but upon hearing Charlie's calls for help, Neri rushes out midway through. Curious as to why someone would steal recordings of whales, Commander Lucas decides to look into Dianne's research and discovers all about Neri.

Jason and Brett eagerly await the return of Neri and Charlie–as does UBRI's Dr. Hellegren who wants to study just one of the returning humpback whales, Charlie. Jason and Brett go to Neri's island to prepare for her return and find a silver pendant inside an unusual flower. When Dr. Hellegren's helicopter crashes into the ocean, Charlie calls to Neri who goes to help him but ends up being taken captive. Neri manages to escape, with a little help from Charlie, but she does so only moments before Hellegren is rescued by Captain Sam Phillips, one of the new arrivals on ORCA. Dianne's research contract is extended another six months by ORCA's new commander, her son however soon proves to be a challenge for the others. Jason and Brett welcome Neri home.

Jason taks driving licene foor the boat and gets out to sunk a net. The whale charle{} gets stuck in the net and Neri tries to save him but gets also stuck. Jason saves her and later she shows them her island. They promise to keep her and the island as a secret.

The kids locate Mera. Her adopted name is Jane Seaforth, and after being bounced from foster family to foster family, she is now living at an institute for gifted children. Dr. Hellegren has also found Mera and wants to take her to UBRI where he can study her. Dianne and Winston ask Neri to help with their survey while the others go ashore to find Mera. At the institute, Jason and Vanessa talk to Mera and she promises to go with them if they prove she can trust them.

Leaving the cave to find help, Jason is found by Jackhammer who drives him back to the others but won't take them with him citing a legend about a ""whale woman"" who was pursued after leaving the very same cave. Winston locates the group in the outback but Praxis, after intercepting Winston's transmissions to the region, head out to capture the trio. Hauser and Shelby meet up with Jackhammer who leads the agents astray long enough for Jason and Brett's father to arrive in a helicopter to rescue Neri and the boys. Before leaving, Neri gives Jackhammer the golden ankh for safekeeping.

As the red virus spreads through the ocean, Jason must restrain Neri from going to Charlie's aid. Through the secret passage from her cell, Mera gains access to the central core of the pyramid and uses it's power to send a telepathic message to Neri. Richter, along with Paul and Brett Bates once again are before Madam President of the Global Union but this time, with the red virus unleashed, she grants Praxis the authority to attack the pyramid. Shersheba encounters Neri in the ocean, she demands that Neri hand over the ankh to ensure the safety of both Earth and the Ocean Planet. When Neri goes to ORCA, she is spotted by Louis who quickly informs agent Shelby, but Helen soon erases all traces of Neri's arrival, affectively destroying Louis' credibility with Shelby. Jason goes to the underwater pyramid to deliver the terms under which Neri will hand over the ankh to Malakat.

Vanessa and Jason go out on a mission with the boat but Neri warns Jason that an earthquake is coming, so they return. Commander Lucas gets angry but the earthquake is for real and Damien and Lee get stuck in a room leaking water. Froggy pulls a trick with the computer called HELEN which stands for Hydro Electronic Liaison Entity 3000{} to try to get them out.

Suspecting a connection between Neri and Jane Seaforth, Dr. Hellegren sends UBRI agents Forsyth and Liselle to ORCA to learn as much as they can about the two girls. Mick is assigned to Dianne's mission to map the ocean floor and an effort must be made to keep him from finding out about Neri who is still assisting Dianne. Mera dislikes living on Neri's island, but after Neri shows her around she begins to like the place. Sam volunteers to process the survey results for Dianne and in doing so locates a large and valuable titanium deposit. 1998 AWGIE Award Nominee: CHILDRENS: Screen Original (Ocean Girl Ep 21 - Annie Fox)