This story takes place long after "The Adventures of Sharkboy and Lavagirl". And recently after "We Can Be Heroes" .
Sharkboy and Lavagirl got married, and shortly after, they have a young daughter together named, Guppy, and it was Sharkboy who picked out her name, and the reason behind that has something to do with his past.
So after the events of "We Can Be Heroes", Sharkboy, along with his loving wife, Lavagirl, and their little girl, Guppy, are having a family vacation on a tropical volcanic island in Indonesia. They were having a great time.
The family was having their picnic lunch, Lavagirl had her lava rocks, Sharkboy had his sushi, and Guppy had sushi too, but her mother cooked it for her. She likes having her fishy meals warm and crispy.
And after lunch, Guppy was having a lot of fun playing her parents. She played tag on the beach and hide-and-seek near the foot of the volcano with her mother, and she went swimming with her father in the ocean, they raced around the island, and swam in the coral reef with her father's tiger and bull shark friends. And later, Guppy used her water powers to make waves and went surfing and wiped out a few times, but she just laughed it off.
Several hours later, the sun was setting, and the sky became orange. Sharkboy was sitting next to Lavagirl on the beach admiring the beautiful sunset, and Guppy fell asleep on her mother's side, she was very tired from playing all day. So they brought her to their beach hut, put her pajamas on, gave her her favorite plush great white shark toy, and put her to bed.
"I remember my father used to put me in bed the same way I do with Guppy when I was her age", said Sharkboy as he gave his daughter a good night kiss on the head.
"And he loved you very much", said Lavagirl, giving her a good night kiss too.
"Yeah, he did", he said. Then, some tears were coming out of his eyes, and he started sniffling.
"Are you okay, honey? What's wrong?", asked Lavagirl.
When Sharkboy closed Guppy's door, him and Lavagirl went outside and sat on a rock. And Sharkboy was starting to cry.
"I just wish that I knew where my father is right now", said Sharkboy. "I've searched for his submarine in every trench, every sea, and every ocean in the world. But I still haven't found him!" He started sobbing and with his hands on his face.
Years ago, after Sharkboy and Lavagirl returned to Earth from Planet Drool, he began his search for his father's submarine. But as time went on, and after he married Lavagirl and had Guppy, Sharkboy still never found his long-lost father.
"Oh, honey", said Lavagirl, trying to comfort her husband without burning him.
"You and I both know that your father is still out there, desperately searching for you as much as you are searching for him. And even though it's been many years, you still haven't given up hope, and that's what I love about you. And I know that when you do find your father, it is going to be a wonderful and happy reunion for the both of you. And he'll be the best grandfather to our little Guppy."
Sharkboy started to smile and wiped away his tears.
"You always know just what to say," said Sharkboy, giving his wife a kiss on her lips. It burned him a bit, but he was used to it.
"And I do hope that you're right about my father being alive out there somewhere, our reunion, and him meeting our daughter. And I hope that he hasn't given up either, I would never give up on searching for you or Guppy if either of you get lost."
"Because nothing is more important than family", Lavagirl said with a smile.
As the sky was getting dark, the moon rose up, and the stars appeared. And when Lavagirl went to the volcano to go to sleep, Sharkboy looked up into the sky. And when he saw a shooting star, he made a wish.
"I wish from the bottom of my heart that me and my father will be reunited", he said closing his eyes. It was the same wish he has been making ever since he got separated from his father as a kid.
Then Sharkboy went to bed in the beach hut.
But somewhere, across the world, someone made the same wish.