Families who loved The Unknown by K. A. Applegate often look for books with a similar feel. These 20 recommendations were selected for their similarity in style, theme, and reading level.
A parent would reach for this book when their middle-schooler is beginning to grapple with the complexities of secrets, the burden of responsibility, and the realization that authority figures don't always have all the answers. It is an ideal choice for a child who feels like they are carrying a heavy weight and needs to see that even daunting, life-altering challenges can be managed through teamwork and steadfast loyalty to friends. In this installment, Cassie and her friends must infiltrate a top-secret military base to prevent an alien invasion from seizing proof of extraterrestrial life. Beyond the high-stakes science fiction plot, the story explores the emotional toll of leading a double life and the ethical dilemmas of war. It is age-appropriate for readers 8 to 12, offering a safe space to explore themes of bravery and accountability while providing a fast-paced, engaging mystery involving animals and high-tech secrets.