Men must fall for their children to rise. But not all children are born to lead. Following the events of PictureHouse, Amelia and Dallas have been provided refuge at the Vanderbilt's second home in California, where Amelia's brother, Callaghan, has been forced to live in hiding following his failed treatments at PictureHouse. However, their reunion is far from comfortable. With Governor Creel in critical condition, Xaver must assume his father's position as interim Governor of Michigan, leaving both Michigan and California in disarray. His sole motivation is to capture Dallas and thus prove himself worthy of the title to the other governors as well as the people of Michigan. Cyrus, on the other hand, has secrets he must confront while Amelia develops a plan to protect not only Dallas from the new governor's grasp, but also the life of someone Xaver is unaware of. Compound is the final book in the Gemini Letters trilogy.