Author's note: "(...)" is any language other than English but primarily Jumba's native language.

Chapter One: Experiment 623

Seven years prior to "Lilo and Stitch" and thirteen years prior to the major events of this story…

Doctor Jumba Jookiba smiled and laughed as his latest experiment was energized. "(Yes! Six-two-three is my most evil experiment yet!)" He laughed evilly as the creature dubbed "623" came into being. She had the appearance of the later experiment 626, but had red pupils set in her black eyes that resembled the "recording" symbol on a video camera, and had dark pink fur with white spots scattered around her body. "(You, my evil creation, will be able to lift objects 2000 times your natural size, be indestructible in your natural form, and blend in with the natural population of any world. For you are created to infiltrate and destroy the world you are unleashed upon!)" The creature laughed maniacally before it was dehydrated. Unfortunately for Jumba, his lab would be raided in a few days' time and the experiment would seem to be lost in the bustle of the raid.

On the island of Kauai, a younger Nani played with her parents. The family was happy. Sprinting and playing around the beach, they ran and laughed as Nani's father chased her. Nani laughed as her mother and father played with the girl, but her attention was drawn to a round hole dug into the soft sand about three foot from the water's edge. Nani looked at the hole and picked up the strange blue pod. "623?" The girl mumbled to herself in confusion as she turned it and read the number. Before her parents could see, Nani attempted to put the round object in a bag she used to collect shells. Her grip slipped on the pod. Once it fell into the water, the pod generated a field of yellow energy then exploded out in a short-lived blast of white light. When Nani was able to look again, she screamed at the sight of the experiment, but it didn't attack her. Instead, two red beams shot out from the experiment's eyes and scanned the girl. The creature then turned white and changed into a baby girl. "Babies come from Outer Space?" Nani questioned in confusion before she picked up the infant and carried her to her parents.

Now…

Jumba was puzzled. To his knowledge, Lilo and Stitch had successfully rehabilitated every experiment save one. "Six-two-three, where are you being?" He mumbled as he studied the database's notes on his lost experiment. The rotund alien sighed and scratched his chin. "Curse my evil genius for the making of you almost undetectable!" He groaned. Then, a thought hit him. "To hide, Six-two-three would be needing a second DNA helix in her cells!" He said triumphantly. Before he could have the computer scan for that unique genetic anomaly, a scream tore through the Pelekai Household.

Stitch ran to Lilo's side. "(What's wrong?)" The blue experiment asked in worry for his friend as he put a hand on her shoulder gently. Lilo shivered. "I…I saw one of your cousins. She didn't speak like you. She spoke English!" Stitch wasn't that surprised. Many of his cousins could speak flawlessly in English. "(Why does that surprise you?)" He asked her. Lilo blinked. She could swear she heard Stitch speak in perfect English. "You don't get it, Stitch!" Lilo said as she began to sob. "Lilith…she destroyed everything, and she even…" Lilo trailed off and looked at Stitch in worry. Then, she went on. "Before I woke up, she told me, 'We will soon be one again.' When she jumped into me, I woke up." Lilo told Stitch with tears. "(Don't worry, Lilo. We'll figure this out.)" The experiment said with his best smile as he wiped away her tears with a gentle claw.

Nani shivered as she listened to Lilo relay her nightmare to Stitch. Ever since she encountered other experiments, Nani knew this would happen to her sister sooner or later. The woman ran down to Jumba's room and glared hard at him. "What's happening to my sister?!" She growled with fireballs in her eyes. "What be the meaning with all this anger?" He asked her. "I discovered a pod thirteen years ago and accidentally activated it, Jumba!" The alien sat up in shock at this. Could it be?! The scientist thought in surprise as he continued to listen intently to Nani's story. "It activated, scanned me, and turned into Lilo!" Jumba shivered. "Little girl is six-two-three? Are you being sure?" Nani nodded with a glare. "I wouldn't lie about my sister, Jumba!" Jumba held up his hands in surrender. "I be needing blood sample from Little Girl to be making sure is experiment six-two-three." He told her. Nani nodded and produced a napkin with blood on it. "Lilo got in a fist fight with Mertle a few days ago when this all started." Jumba nodded as Nani continued. "I was sure Mertle broke Lilo's nose, but by that night, it was healed completely. "Interesting…" Jumba mumbled. "…it would be seeming that Little Girl is slowly combining with six-two-three original program." Nani paled when she heard this. "Will Lilo be ok?" Jumba shrugged. "Eh…hard to say how changes will be effecting Little Girl. We must be watching her closely from now on." He said to Nani. The woman nodded as she heard Lilo and Stitch coming down the elevator.

Lilo sighed and forced herself to eat what Nani fixed for breakfast the next morning. "Happy birthday, Lilo!" The sound echoed in Lilo's ears as if a megaphone was right next to them. She screamed at the sudden pain and put her head down on the table as Stitch looked at Lilo. "(Is Lilo ok, Nani?)" He asked softly. Lilo shivered and responded without pause. "No, Stitch, my ears hurt really bad." She said to him without thinking. As the ringing slowly died in Lilo' s ears, she became aware of Jumba whispering notes in his native language. "(Experiment is here on Earth and has taken the form of a native girl. I will be watching closely.)" Of course, Lilo heard perfect English again. This confused her because Jumba couldn't quite get a few rules of English grammar down. She shrugged it off and headed to school with Stitch. I wonder if Mertle is the experiment Jumba was talking about. She thought with a small grin at the possibility.

Please Read, Review, and be kid. This is my first "Lilo and Stitch" fic.