A strange teenage girl suddenly appears in a small town in Pennsylvania. When she says, "My name is Mary Smith, and I am new in town," it sounds like she is practicing lines in a school play.

Dylan Michael Olson, 16, doesn't care if that is her real name, or where she is really from. When she smiles at him, his world changes from gray to technicolor, from depression to total bliss.

Dylan's mom, Louisa May, believes that Mary is an abused child, a runaway seeking safety and family. A survivor of child abuse herself, Louisa opens her home and her heart to Mary, surrounding her with motherly protection.

As Dylan and Mary fall in love, the holes in her story start to pile up. When Mary suddenly disappears, Dylan and Louisa are willing to do anything to find her, including seeing the Universe in a totally new way.