Can the teachers write a lesson plan to overcome a ruthless killer? At her twin brother's funeral, Lily touches his casket, whispering a Scottish blood oath: "If your killers were from the Diabhal, then they should know that I'll be a Deamhan and will pursue them until your soul is avenged." A middle school science teacher, Lily convinces three colleagues to help her avenge the murder. They risk all in their pursuit,...