Marah Levi is a promising violinist who excels at school and can read more languages than most librarians. Even so, she has little hope of a bright future: she is a sparker, a member of the oppressed lower class in a society run by magicians.

Then a mysterious disease hits the city of Ashara, turning its victims’ eyes dark before ultimately killing them. As Marah watches those whom she loves most fall ill, she finds an unlikely friend in Azariah, a wealthy magician boy. Together they pursue a cure in secret, but more people are dying every day, and time is running out. Then Marah and Azariah make a shocking discovery that turns inside-out everything they thought they knew about magic and about Ashara, their home.