To save her father's future, she'll have to change the past.

The one thing thirteen-year-old Margaret O'Malley is sure of is that her father is innocent. So when the unthinkable happens and he's sentenced to death by the cruel Judge Biggs, Margaret is desperate to save him. She'll do whatever it takes, even if it means using her family's secret - and forbidden - ability to travel through time.

Margaret's only hope is to stop the chain of events that turned Lucas Biggs into a corrupt and jaded man. With the help of her best friend, Charlie, and his grandpa Josh, Margaret jumps back in time to a year when everything in her town was going wrong - a year that changed Lucas Biggs forever. Together with a then-thirteen-year-old Josh, Margaret sets out to change the past. But the rules of time travel are strict, and as the forces of history resist, Margaret is running out of chances before she will be pushed back to a present where her father is doomed.

Written by New York Times bestselling author Marisa de los Santos and her husband, picture book author David Teague, this spellbinding story proves that sometimes good needs a little extra help to triumph over evil.