This review published by Brigham Young University's The Children's Book and Media Review

Gillian Seagret knows that almost everyone thinks her father is a crackpot, but she doesn’t believe them. To her, his Cold War conspiracy theories about the lost technology of Dr. Aloysius Underberg are legitimate and “they” are out to destroy his credibility. When she finds a missing page of Dr. Underberg’s diary, Gillian is convinced that she has found the start of a space-themed puzzle that will help her prove that her father was right and lead the way to Dr. Underberg’s most important invention. With the help of her younger brother, Eric, her best friend, Savannah, Howard, a classmate obsessed with space, and Nate, Howard’s older brother who is concerned about everyone’s overall safety, the group finds their way to a secret underground bunker. Chased by others who want to use Dr. Underberg’s technology for profit, the kids have to problem-solve their way out and solve Dr. Underberg’s last mystery.

Cold War conspiracy theories might not sound appealing to some readers, but fans of adventure, good characters, and survival stories will be thrilled with this book. The characters and their relationships with each other are wonderful. Gillian is deeply loyal (perhaps to a fault), Eric just wants a normal life but also cares about his family, Nate is trying to protect everyone and knows that he will likely be held responsible for what happens, Savannah is highly intelligent but worries that being smart will make her less attractive to boys, and Howard is still trying to learn how to interact with other people. These different personalities and sibling relationships make a powerful story of working together in difficult situations. This is a thrilling middle grade book full of conspiracy theories, details about the Cold War, and adventure for the middle grade reader.