In a corner of the world where reality weighs like a stone, a young boy named Conor O'Malley faces the difficult battle of growing up while his cancer-stricken mother fights for her life. Loneliness and pain become his inseparable companions, until one night, an ancient and magnificent tree transforms into a monster that arrives at his window. This being, with a deep and wise voice, is not merely a product of Conor’s imagination; it is a balance between nature and human conflict.
The monster offers him a curious proposition: to tell him three stories in exchange for a moment in which Conor must share his darkest truth. As the narratives unfold, they intertwine with the boy's real life, exploring themes of loss, pain, and the immense weight of family expectations. Each story from the monster reveals lessons about courage, truth, and the internal struggle that everyone faces at some point.
As time progresses and his mother's condition deteriorates, Conor must confront his own fears and resentments, as well as his inability to cope with the responsibility that has been placed upon him. Through this blend of fantasy and reality, he embarks on an emotional journey that will not only change his life but will also teach him the true meaning of acceptance and unconditional love, even amidst the greatest of sufferings.