To save her father's future, she'll have to change the past.When the cruel Judge Biggs wrongfully convicts Margaret's dad of a crime he didn't commit, Margaret is determined to do something, even if it means using her family's secret— and forbidden—ability to time travel to save her dad.With the help of her best friend, Charlie, and his grandpa Josh, Margaret jumps back in time to stop the chain of events that turned Lucas Biggs into the corrupt and jaded man who sentenced her dad. But the rules of time travel are strict, and the forces of history resist Margaret's attempts to alter the past. Margaret is running out of chances before she will be pushed back to the present, where her father is doomed, and where, without Judge Biggs's help, Margaret will lose her father forever.