| 1 | Clarke | Griffin | One of the protagonists. The girl Well falls in love with. |
| | Thalia | | Clarke's former cellmate and only friend. |
| | Lise | | Clarke's cellmate. |
| | Dr. | Lahiri | The council's chief medical advisor. |
| | Chancellor | Jaha | Well's father. The chancellor. |
| 2 | Wells | | The chancellor's son. Aka: Chancellor Junior. |
| 3 | Bellamy | Blake | Cotton's friend. The boy who hostaged Chancellor Jaha. |
| | Colton | | Bellamy's friend. A guard. |
| | Octavia | Blake | Bellamy's sister. One of the prisoners. |
| 4 | Glass | Sorenson | Well's best friend. |
| | Cassius | | One of the prisoners. |
| | Luke | | One of the guards. Glass's ex-boyfriend. |
| | Carter | Jace | Luke's roommate. |
| | Camille | | Luke's childhood friend. |
| 5 | Lucy | | The oldest hominid remains earthborn. |
| | Lilly | | One of the prisoners. |
| 6 | Graham | | The boy from Phoenix. |
| 8 | Sonja | Sorenson | Glass's mother. |
| | Rhodes | | The vice-chancellor. |
| 10 | Asher | | An Arcadian. |
| 11 | Cora | | Glass's friend. |
| | Huxley | | Glass's friend. |
| 24 | Ali | | Luke's colleague. |
| | Bekah | | Luke's guard friend. |
| 36 | Eliza | | The girl from Walden. |
