What do you do when you have to constantly watch bad things happen but aren't allowed to fix them? Lacey Hallowell is proud to be a time-traveling historian, but she is tormented by her institution's policy--observe only, don't interfere. After getting in trouble for trying to alter a pivotal historical moment, Lacey reconnects with an old friend who is a member of a group with a secret and dangerous mission. If Lacey joins them, she may have the opportunity to make the world--past and present--a better place. But can she trust the group and leave her entire life behind?