Elizabeth Fields, known as Liz, was the daughter of scientist Dr. Weston Fields and Ashley Fields. Her father conceived the Eden project, creating robots to support humanity after environmental destruction eroded his faith in mankind. Elizabeth cherished her robotic dog companion, Emily, who often presented her with gifts like apple blossoms and seeds. She tragically succumbed to an illness before the Eden project's realization, an event that devastated Dr. Fields. Her death deepened his despair, ultimately driving his decision to transfer his consciousness into a robotic body, becoming the antagonist Zero.

Centuries after Elizabeth's passing, Emily demonstrated persistent devotion by visiting her grave within Eden Zero's ruins, bringing gifts for over a thousand years. This recurring act connected the past to the story's present. Elizabeth's existence and memories, particularly her bond with Emily and her father, later proved crucial for resolving the central conflict. Her name and specific phrases became integral components for recovering the password needed to awaken the remaining humans from cryogenic stasis.

Primarily, Elizabeth functions as an emotional catalyst within the backstory, motivating Dr. Fields' transformation into Zero and influencing key plot developments through her legacy: Emily's enduring behavior and the symbolic significance of apple-related motifs.