An elderly man known as a "gummy," who lives alone in the stackboxes and holds a treasured manuscript. His calm demeanor and knowledge make him a valuable companion to Spaz.

A largely mute 5-year-old orphan who helps Spaz track down Ryter. He follows Spaz on his journey and proves useful due to his agility.

A teenage proov from Eden, who is genetically enhanced and destined for leadership. She shows kindness and uses her status to help others, often traveling to the Urb to distribute food.

Spaz's 12-year-old foster sister, suffering from leukemia, who shares a deep bond with him despite his exile. Her intelligence and curiosity are notable.

The ruthless latchboss of Spaz's area known for his unpredictable behavior. He leads the Bully Bangers and has a complicated connection to Spaz.

A fierce leader of the latch where Bean lives, known for enforcing strict rules. She bans probes and maintains control through her henchmen, the Vandals.

The boss of the underground network in Lotti Getts' area. He operates secretly within the trading district and is unimpressed by the proovs' status.

A former latchboss who is now incapacitated due to prolonged use of a probe. His territory has declined into chaos under the leadership of his former henchmen.

Lanaya's father known as her "contributor," who is smart and enjoys playing chess. He is initially skeptical of normals but becomes supportive of Bean's treatment.

Lanaya's mother known as her "contributor," who adopts Little Face during the group's stay in Eden. She is nurturing and creates a bond with Little Face.

Spaz and Bean's foster father, who prioritizes Bean's safety over Spaz's presence in their family. He is protective yet conflicted, sometimes resorting to harsh methods.

Spaz and Bean's foster mother, who is often cautious but advocates for the bond between Spaz and Bean. She influences decisions about Bean's treatment.