| A | B |
|---|
| Overlanders | Humans born in the Overland |
| Gregor | An eleven-year-old New Yorker |
| Boots (Margaret) | Gregor's youngest sister |
| Lizzie (Elizabeth) | Gregor's middle sister |
| Gregor's Dad | A high school science teacher |
| Grace | Gregor's Mom |
| Senile | Gregor's Grandmother |
| Mrs. Cormaci | Gregor's neighbor in his Overland apartment |
| Larry | Gregor's asthmatic friend at school |
| Angelina | Gregor's “actress” friend at school |
| Bartholomew of Sandwich | author of all the prophecies the Underlanders adhere to.(Deceased) |
| Luxa | The crown princess of Regalia |
| Vikus | Luxa's grandfather, rules Regalia |
| Solovet | Luxa's grandmother, Regalian army's leader |
| Mareth | Regalian soldier and military trainer |
| Henry | Luxa's royal cousin |
| Hamnet | Luxa's uncle, father of Hazard and twin of Judith |
| Nerissa | Luxa's cousin, Henry's sister, has visions of the past or future, and is the interpreter of Bartholomew of Sandwich's prophecies |
| Neveeve | A Regalian doctor, develops a plague |
| Dulcet | A kind and clever Regalian Nanny |
| Howard | Luxa's eldest cousin |
| Hazard | The six-year-old son of Hamnet |
