Classmates Alice, Julie, and Reika wonder if that was Lain they saw at the nightclub Cyberia. To find out, they invite Lain to go with them to the club.

As the Knights activities make the evening news, a strange man named Nazumi wanders the city with machines strapped to his body. People on the WIRED are asking: ""Who is Lain"". Meanwhile, the two MIB agents take Lain to the Techibana offices where Lain's identity is challenged by a man; how well does she know her parents, her sister, herself? Can Lain answer him?

A documentary about Roswell gives Lain some valuable information about the pioneers of the WIRED. Later, at the Cyberia, J.J. tells Lain that she left something the day before and hands her an envelop with the Knight's logo on it. The envelop contains a chip. Believing this was the other 'Lain's' doing again, she decides to call Taro's bluff and go on a 'date'. Taking him to her room, Lain demands that he tell her what he knows. Together, with Taro's information and the mysterious chip, Lain finds out more then she expected.