Guilmon tells Takato that last night it felt as though he disappeared and went someplace else, which Takato interprets as a dream. Then his legs and tail slowly start to disappear when he is in a certain area, but don't when Guilmon is out of this area. Takato tells Henry, who says that maybe some Digimon can't last long on Earth and are pulled back to the digital world, or that the world eliminates them as if they were a virus. Takato doesn't want Guilmon to leave.
Riley tells Yamaki about the strange activity she noticed.
In Takato's class, Miss Asaji tells her class about a tunnel that's for use when the rain causes flooding, and says it's a useless lesson because everyone knows about it already (except Takato). When Takato gets back to Guilmon's cave, he finds Guilmon playing with Calumon, who eventually runs off.
Yamaki tells the researchers what Hypnos does, monitoring any electronic activity, and a researcher tells him that they could be treated as criminals if the general public found out about it, and tells him to find a way to stop the anomalies from coming through and to eliminate the ones they have.
While Takato and Guilmon look for Calumon, Guilmon suddenly turns and runs into an alley, where Rika and Renamon are. Guilmon thinks Takato and Rika are going to fight, but after a brief argument, Takato says he and Rika got off on the wrong foot. They go to Rika's house, where Takato tells Rika about his dream where he saw her and Renamon. When Rika's grandmother appears, Renamon hides Guilmon behind the corner. Grandma wants Takato to stay with them for a while, but Rika doesn't. After she leaves, Takato asks Rika if Digimon can disappear for no reason. Rika says probably, because Digimon are just data.
As Takato and Guilmon head back to the park, Guilmon disappears. Takato thinks he is gone, but finds that the tracking device on his digivice is still active, and pointing toward the tunnel. Takato gets Henry, Terriermon, Rika, and Renamon.
Yamaki invents a program called Yuggoth, which will disinfect the area in which the anomaly they have been tracking, a digital zone, has appeared. Riley tells him unapproved programs are forbidden by the "guys upstairs", Yamaki says they can't understand the technology or the existence of the digital world.
When they enter the spot where Guilmon disappeared, Terriermon and Renamon begin to disappear as well, so Henry tells them to leave the area. As Takato and Henry head into the tunnel to find Guilmon, Rika initially stays behind, not caring whether Digimon disappear, but eventually goes with them. Eventually they find the digital zone responsible for Guilmon's disappearance. As Yamaki prepares to delete it, Takato, Henry, and Rika enter it. Their digivices lead them to Guilmon, who is tied up by energy ropes. Yamaki activates Yuggoth, which begins to erase the digital zone. Henry and Rika throw Takato at Guilmon, who breaks free of his ropes and creates a road to lead them out of the digital zone before it is destroyed.
- Though not a character, the digital zone serves as antagonist in this episode.
- This is the first time Yamaki's face is clearly seen. Before any scenes with him were either behind him or his head mostly out of view.