Cronin uses his vampires, or virals, to suggest that an essential aspect of human nature is mortality. When Professor Lear enters the Bolivian jungle, he reports that he may have found the cure for death. However, what he finds turns out to be a virus that robs humans of their humanity, turning them into virals. In the First Colony, the virals are considered to be animated humans without souls. The savagery of the virals seems inhuman compared to the fiercest humans that defend First Colony.

Amy is also immortal, and though her innocence is unlike the rest of the virals, she, too, is presented as an inhuman figure. When Amy is rediscovered, she seems to exist outside the human realm, without coherent thoughts or feelings. Furthermore, her role and associations suggest that she has taken on an angelic or divine role within the novel, a comparison that is heightened by her constant yearning to make snow angels as well as Lacey’s description of her as an “ark” for humanity. Although Peter receives several vials capable of transforming people into virals like Amy, Amy destroys them. She justifies her actions because she does not want Peter to become like her, which Peter interprets as an act of mercy.

After the death-row inmates escape from Colorado and overrun America, many human survivors commit suicide out of despair. Even members of the First Colony, a society that has survived for more than ninety years, find hope too painful to endure or nurture. In contrast, Peter’s father used to search for other human survivors, which Peter comes to understand as an act of hope. Peter’s brother, Theo, explains that hope is more difficult than courage (acting rather than dying).

Cronin uses Sister Lacey to suggest that faith and hope are intertwined. Lacey repeatedly calls on others to believe in God’s plan and will, often assuring others that they will know what to do when the time comes. Because she has faith, Lacey is able to maintain a sense of hope for the future. Where many see the hand of God in the end of American civilization, Lacey focuses on Amy as a manifestation of God’s will. She urges Peter to envision the virals as a second Biblical Flood and to see Amy as a second ark. For Sister Lacey, hope requires faith.

Cronin’s depiction of Amy makes use of Christian symbolism and archetypes, and this post-apocalyptic story can be viewed as an allegory for the Second Coming of Christ. Under this interpretation, Amy can be seen as a savior figure. Peter and his fellow colonists form a new version of the Twelve Apostles. Peter’s name alludes to Simon Peter, Jesus’ first apostle. Just as Jesus urged his followers in the Bible to find salvation through his blood and body, Alicia returns from the dead when she is injected with a vial of Amy’s virus. Finally, many of the virals are said to have no soul, yet they seem to be saved from this form of damnation by telepathically communing with Amy. In other words, through Amy, the virals are able to find salvation just as Christians hope to find salvation through Christ.

Cronin focuses on the fallibility of human nature, including pride and lust for power. The military falsely believes that they can control the death-row inmates, and as a result, North America—perhaps all of human civilization—is destroyed. Rather than leading to security, the military’s yearning for military power is corrupted. This corruption is particularly revealed through Richards’ willingness to use Amy, a six-year-old innocent, as...