"A Monster Calls" is a novel by Patrick Ness that tells the story of a young boy named Conor O'Malley who struggles with his mother's illness. Conor is visited by a giant tree-like monster that comes to help him confront his fears and emotions. The monster shares three stories that challenge Conor's understanding of truth and morality. As Conor navigates his difficult life, he grapples with feelings of anger, guilt, and sadness. The story explores themes of loss, grief, and the complexities of growing up, ultimately leading Conor to find his own voice and acceptance in the face of adversity.