"The Last House Guest" is a mystery novel by Megan Miranda that revolves around the death of Aimee and the impact it has on her friend Sadie. Set in a small coastal town, the story explores themes of friendship, secrets, and the complexities of relationships. As Sadie investigates Aimee's death, she uncovers hidden truths about their lives and the people around them. The narrative delves into the dynamics of the community, revealing how perceptions can be distorted and how grief can lead to unexpected revelations.