Tender
Tender is a surviving member of a suicidal cult called the Creedish church. He is also a terrorist and hijacker, not unlike the nightmarish episodes of 9/11. However, he is simultaneously a true American celebrity, he thinks, because he is the last surviving member. The whole world watches patiently to see when and how he will kill himself. When he hijacks a plane, that is perhaps not what they had in mind.
Fertility
Fertility is a dubious sibling in the novel. She shows up when crises get out of control, and sometimes she saves the day. But, when Fertility is found to be pregnant, she tells Tender and leaves him, moving to Australia. Fertility is Tender's saving grace, and when he feels like she is abandoning him, he decides to hijack her plane and crash it, murdering her and everyone else on board.
Adam
Adam is Tender's dubious twin brother who always commits acts of violence and murder. Suspiciously, he seems only interested in killing the very same people Tender himself would like to kill, and when Tender beats Adam to death and escapes to Oregon, the question must be asked: Is Adam even real? Is he just having a schizophrenic breakdown because of the intensity of the car wreck and because, perhaps, Tender is the real murderer? Is Adam a figment of Tender's imagination?