In the novel The Hunger Games, the nation of Panem has a Capitol that rules over twelve districts. Every year a lottery is held to choose two young tributes from each district to compete in a gladiator-style reality TV competition where they fight to the death. Katniss Everdeen’s worst nightmare comes true when her little sister Prim gets selected to be a tribute, so she volunteers to go in her place. Katniss’s selfless act of volunteering to take her sister’s place can serve as an illustration of the substitution of one person so another can go free (Suzanne Collins, The Hunger Games [New York: Scholastic Press, 2008]). (Of course, since Panem is an evil empire and Katniss an imperfect human, the analogy breaks down, but it does show us the power of a sacrificial act on behalf of another.)