Berry is a girl living in the data-managed city of Tom Sawyer Island. Her hobby at the moment is trying to catch Phantom Zero, who's believed to be behind the cases of Love loss known as the Zero Phenomenon. One day, when she heads into town to get the broken Deco in one of her eyes fixed, Berry runs into a kid who seems like a ghost, due to being unable to be seen with Deco. Suspecting she may have finally found the Phantom, Berry begins her chase.

Berry and Hack are somehow able to escape from the Hyperverse that Phantom Zero pulled them into. But before long, Hack is apprehended by the customer center, who are investigating the Zero Phenomenon. The next day, Berry wakes up on the veranda of her apartment, and after trying to explain what happened, her friends point out to her that there is no evidence of Zero Phenomenon having occurred, much less of the kid she encountered. Not taking no for an answer, Berry decides to dig up proof behind the Zero Phenomenon.

Berry catches wind of a ramen cart that nobody knows the location of. In order to find it, Watson begins checking rumors from all across the island. Berry suggests that the detective club search for the cart, but the other members aren't interested. As Berry and Watson investigate the rumors, Watson receives a tip on the location of the cart. In pursuit of ramen, Hack, Berry, and Watson set out to find it.

Berry is helping Hank sort through the junk that he has salvaged at the harbor when they encounter an old friend of Hank's, named Will, who informs them about an older model of satellite that's expected to crash down into the nearby sea. Back at the agency, the peacock feather-like circuit that Watson received from Analytica is being analyzed. When Hank returns, he insists that they all head to the area Will tipped them off about.

When Finn was young, his family lived in a slum where garbage tended to be dumped. One day, his brother brings him an older model of Deco that should be easier for Finn to use due to his Deco-Sickness. With it, Finn accidentally discovers that the local purification systems are broken. Believing this is what has caused his home to become polluted, he uses the Deco that he got from his brother to request that the customer center fix the purification system. But because he isn't registered as a citizen, his login is flagged as illegal, which leads to his request not being answered.

Thanks to Doron and his drone friends, Berry, Hack, and Finn are able to reach Mark Twain, a strange facility floating in the sky. By using the Angelfish club card they had previously obtained, they manage to get inside, where Berry and Hack enter Mark Twain's rendition of the Hyperverse. What they discover appears to be a labyrinth. Knowing that all the secrets of Tom Sawyer island must be contained within, Berry and Hack start searching for Phantom Zero's identity.

A young girl awakens in a empty white space. She's enjoying a happy life with her parents, staring out at her pet peacock. But then, from out of nowhere, Berry appears. The girl is surprised, and attempts to run away.