In this book, Luke Garner is a boy who has two older brothers. This is a problem because in their society, third children are forbidden. So Luke has to hide all the time. Eventually, in the book, he meets Jen (Jennifer Rose Talbot). Jen is also a third child. Over the course of the book, she teaches him a great deal about their society. She is eventually killed at a protest rally.
Jen's brothers (actually they are step-brothers from her mom's first marriage) are nicknamed Bull and Brawn. Their real names are Buellton and Brownley.