The group "Crossing the Border" chose four people to survive in a bunker after a deadly Avian Flu pandemic wiped out the human population: a male doctor to maintain the health of the group and teach medical skills, a female university professor of physics and engineering to help design structures and solve problems once the survivors leave the bunker, a female scientist specializing in biology and agriculture to control the greenhouse and teach farming, and a male army officer to perform physical tasks, share survival techniques, and provide security.