After beating the first dimensional plane's boss, a new area of Hekseville, Pleajeune, is open to the player. A boy named Newt can be found here and asks Kat if she can help him find his lost friend, who happens to be Echo. After talking to a local student, it is found out that she is somewere in Arquebus Academy. Once Echo is found, she is acting strangely, being overprotective of her bag. Newt tries talking to her but a Nevi comes out her bag and takes over her body making her transform into a giant spider-like creature. Kat is able to defeat her but Echo seems to be upset about the whole incident, claiming that the nevi was only trying to protect her. Newt comforts her by reminding her of their childhood and how they became friends. He reveals that as kids, Echo was the one always looking out for him, even getting a scar after saving him from falling off a tree. He embraces her and claims that he wants to be the one to protect her from now on.
The battle begins with a chase scene where Kat will have to attack the cores on the Spider Nevi's back, while avoiding Echo herself. There is a Nevi Infestation indicator at the top right of the screen. If it reaches 100, then the mission fails and the chase will start over again. The nevi will occassionally stop to attack, making it easier to hit the cores. Once the nevi's health is low, the battle will end when the player touches the blue circle on the screen.
- Her name is likely a reference to the character from Greek mythology. Echo was a nymph who fell in love with the handsome Narcissus, though (as with Newt) it was mostly unrequited.
- She is the second person Kat encounters who displays some control over the Nevi (the first being Alias), the reason being it was trying to protect her from any perceived threats.