The novel’s 11-year-old protagonist, Gregor, is a round character who exhibits significant growth. He embodies empathy, selflessness, responsibility, honesty, and protectiveness. As the eldest of three siblings and the hero who rescued his father in the first book of the series (Gregor the Overlander), Gregor shoulders a deep sense of duty. Even before returning to the Underland, he works hard to support his family, such as through helping his neighbor: “He’d use the money for his family. Because even though his dad was home, there was no way he could go back to his job as a science teacher” (6-7). His concern for others, especially his loved ones, drives much of his decision-making. When Boots is taken, he embarks on the journey to save her without hesitation, showing his unwavering devotion.

Gregor focuses less on his own fate than on Boots’s safety, distraught by his interpretation of the prophecy: “But his mind snagged on one phrase that chilled him to the bone: Die the baby…Die the baby…Die the baby…Boots…” (40). His protectiveness defines him and drives his actions, from keeping Boots close during their journey to blaming himself when he forgets her life jacket.