What is the theme in Running Out of Time by Margaret Peterson Haddix?

Another theme is bravery and heroism. Throughout the novel, many characters make important decisions that test their own bravery. Although Jessie has an amazing journey ahead of her, Ma makes an intense decision to let Jessie go and tell her the truth about Clifton. While Ma believes she cannot go on the journey herself, it is not because she is not brave. Rather, if Ma leaves, she will be more easily spotted by Clifton's men. Ma seems to be an extremely brave person for sending her child out into a world about which she knows nothing. Ma risks her children, husband, and individual safety to cure the rest of the children in Clifton.