Take the Key and Lock Her Up (Embassy Row, Book 3)

New York Times bestselling author Ally Carter returns with the third entry in this runaway series.
For the past three years, Grace Blakely has been desperate to find out the truth about her mother's murder. She thought it would bring her peace. She thought it would lead her to answers. She thought she could put the past to rest. But the truth has only made her a target. And the past? The only way to put the past to rest is for Grace to kill it once and for all.