* Sara: The protagonist, a seemingly average 16-year-old who is secretly a skilled hacker and tech whiz. She gets caught up in a complex web of secrets and danger when her older brother, Ben, disappears.
* Ben: Sara's older brother, who is a talented musician and secretly involved in a mysterious project that gets him abducted.
* Michael: Sara's best friend and a tech-savvy classmate who helps her in her investigation and stands by her side.
* Nick: A mysterious and seemingly friendly stranger who Sara encounters while searching for Ben, but his true intentions are unclear.
* Dr. Davis: A scientist who is possibly involved in Ben's disappearance and the project he was working on. He is a complex and morally ambiguous character.
* Mr. and Mrs. Green: Sara's parents, who are initially unaware of Ben's disappearance and the real danger their daughter faces. They are loving but sometimes clueless about the world their children inhabit.
These are the main characters, but other supporting characters like Sara's friends, Ben's bandmates, and various officials involved in the investigation also play roles in the story.