The book ‘Irreplaceable’ is written by Angela Graham. ‘Irreplaceable’ is the 2nd book in the ‘Harmony’ series. The story is about Cassandra Clarke and Logan West. As the story goes, despite the pain and betrayal, Cassandra must decide whether to protect her heart or risk falling again for Logan and whether her body finds the person irreplaceable. The book analyzes themes of love, trust, and personal growth.