John's 11-year-old brother, who is knowledgeable about survival but struggles due to his diabetes. He experiences conflict with John over decision-making and survival tactics.

A resourceful girl about John's age, noted for her intelligence and practical thinking. She travels with her younger brother and the Lockwood brothers, contributing her logical insights to the group.

Cleverly's younger brother, seen initially as a weak link but soon shows responsibility and resilience. His contribution to their journey becomes more significant as events unfold.

A young family friend of the Lockwoods who, like Stewart, has diabetes. She is a practical and supportive figure, known for her bravery and understanding of her condition.

John and Stewart's father, whose influence is felt through his teachings of self-reliance and survival skills. He is a guiding presence despite being physically absent.

The novel's antagonist, who poses a threat to the Lockwood brothers by stealing their supplies. Despite his actions, there are hints of internal conflict and regret.

Jess’s older brother, who contrasts with Jess due to his protective, sometimes fear-driven decisions during their challenging circumstances.