12 year old Jo Keaton hopes to save her 100 year old home from demolition by the University in her small town in deep southern Illinois. There are only 5 days left as Jo explores the attic and discovers an ancient trunk and a letter hidden in its lining. During a violent thunderstorm, she reads of a ghost seen haunting the rose garden. This mystery galvanizes her to search for a connection to the Underground Railroad, and leads her to learn the horrors of slavery and the dangers of life in a border state during the 1800s and the Civil War.
Jo is impulsive and impetuous but changes dramatically as she realizes there is a cause greater than herself in her journey to solve the mystery of the ghost and save her home. Jo also experiences prejudice that is present in the 40s as she sees her best friend Claire, who is colored, mistreated. The harrowing story told by Claires 100 year old great-great-grandmother of a tragedy she had witnessed at the old Thompson house in 1858 leads Jo into a dark and violent past. Jo also experiences a chilling supernatural encounter that she could and would not reveal to anyone, but that is instrumental in her quest.