With a map stretched out on a Mauler, Lady Jaye tells Alpine, Doc, Duke, Recondo, Gung Ho and Heavy Metal that since Shipwreck knew that the destination for the Joes was Kona Tonga Island, they will travel without him. Shipwreck awakens on a beach and immediately yells Mara’s name. She stands up in the water, flings her hair back and yells Shipwreck’s name and invites him into the water. Elated beyond words, Shipwreck yells a loud “yippee” and dives in. When he surfaces, Mara again kisses him and he states that she doesn’t seem the type to join Cobra. “How would you know?” Mara asks sourly and walks to shore. Slumping down to the beach, she explains to Shipwreck, who lays down behind her, that she did what was necessary to survive in her neighborhood and learned that the only reason someone is nice is when they want something in return.

Shipwreck then realizes that Mara does know the location of the base and calls himself a moron. Walking off to the water again, Mara asks if that’s what Shipwreck wants. He immediately tells her that he wouldn’t mind saving the Nirka’s crew, however, he adds, "If you can’t afford that luxury -"

And he is tackled into the water by Mara and as he gasps for breath, she tells him lovingly, "So I’m attracted to morons." Shipwreck chuckles lightly and replies, “And I’ve got this thing for mermaids.”

The two kiss, but a ship blows a horn and Shipwreck groans, “There goes paradise.”

While pointing to a map, Lady Jaye notes that Cobra has the crew of the Nirka and the ship. Meanwhile, at the underwater Cobra base, Destro tries to persuade the Nirka’s skipper, Captain Jordan, to tell him one or two of the access codes to the hi-tech submarine, however, Jordan only replies with one word - never. And Destro leaves the room and walks to his command station, where Tomax and Xamot pay him a visit in order to tell him that repairs to the Cobra sub are almost complete. Destro says, “Good,” and the twins comment that he doesn’t sound pleased. Destro explains that since Cobra Commander has not been able to capture Mara, he believes it would be wise to abandon the base and scuttle the Nirka with her crew trapped inside.

Inside a room on the Joes' ship, Shipwreck tries to console Mara, who has just learned from Doc that her condition is irreversible. They then hear the call for battle and enter the war room with the rest of the Joes, and Lady Jaye notes that Shipwreck is not an experienced diver. But he replies that he will learn on the job; besides, he adds, he has a personal stake in the matter.

The Joes swim to the base and Shipwreck signals for Mara to stay outside after the Joes blow a door into the base. However, Mara enters the base. Lady Jaye splits the forces and one group encounters a group of Cobra agents while Mara plants plastic explosives around the base, frees Captain Jordan and helps the man knock out the Cobra guards in order to rescue his men. Lady Jaye confronts Destro in his control room, unfortunately, she is knocked out from behind by Tomax and Xamot. “Take her to the lab,” Destro orders the twins, who reply, “You could at least say thank you.”

Setting the lasers to full blast in the lab that converted Mara to a mermaid, Lady Jaye, who is lying down on a table, slides into the laser chamber while the Cobra agents retreat. Shipwreck and the Joes run into the crew of the Nirka and learn that Mara helped them. Shipwreck finds out where she went from Captain Jordan and tells the Joes to shove off without him if he is not back in five minutes.

Mara, who is beginning to feel the effects of being out of water for too long, places another bomb on the wall of the lab and rushes to lift Lady Jaye off of the table. After saving Lady Jaye, she collapses and begins to the ground and begins to gasp for breath - and the timer falls off her belt and is activated. Shipwreck enters the room and Lady Jaye tells him that Mara saved her life and the two Joes run out of the room. Aboard the Nirka, a sailor reports to Captain Jordan that the Cobra sub is leaving, but Jordan doesn’t care about anyone but those Joes who are still inside, even if more than five minutes have passed.

The base erupts and the Nirka is forced to flee. Saddened by the loss of the Joes in the base, one of the Joe divers tries to console Captain Jordan by explaining that he waited as long as he could. But one of the sailors under Jordan’s command reports that Lady Jaye, Shipwreck and Mara are safely swimming to the surface and everyone shouts a happily and loudly: “YO JOE!”

On a beach at Kona Tonga, Mara and Shipwreck hold one another under the moon and she tells him, “There’s no other choice, Shipwreck.”
Shipwreck: “Mara -“
“No,” Mara interrupts, “don’t say it. Please. It’ll only make things harder. Kona Tonga is a beautiful place. I belong here...I belong to the sea.”
She runs away and dives into the nighttime waters. And on an empty beach, a sailor stands in the cold moonlight, slowly waves to the ocean and quietly whispers, “Good-bye, Mara.”