Tally
Tally is the main protagonist of the trilogy. She got captured by Dr. Cable and turned into a special kind of Special - a Cutter.
Shay
Shay was Tally's friend but sees Tally as selfish believes the world revolves around her. Shay also made herself become a part of the Special Circumstances by starting the Cutters group turning her friends Special.
Zane
Zane is Tally's boyfriend who, in the previous novel, swallowed the pill that resulted in his brain damage. Although he loved Tally his slight brain damage became too much of a barrier for her as a special.
David
David was Tally's first boyfriend and is now the leader of the New Smoke movement. He grew up in nature, outside of cities.
Dr. Cable
Dr. Cable is the leader of the Special Circumstances and the one who organized the Cutters. She is the main villain of the trilogy.