In Chapter 15 of Wuthering Heights, the narrative delves into Heathcliff's psyche as he grapples with the haunting memories of Catherine Earnshaw. The chapter unfolds with Heathcliff's increasing obsession with the past, particularly his lost love for Catherine, whose presence looms large in his mind. This obsession manifests itself through his interactions with the other characters and the moors that serve as a backdrop to their tumultuous history.

Heathcliff's behavior becomes increasingly erratic as he is unable to escape the memories that torment him. He wanders the desolate moors, which mirror his inner turmoil, embodying his despair and longing. These landscapes are not merely settings but act as reflections of his emotional state, emphasizing the deep connection between nature and human emotion that is prevalent throughout the novel.

The chapter also reveals Heathcliff's deteriorating mental state, marked by moments of rage and sorrow. His encounters with Nelly Dean, who serves as both a confidante and a witness to his anguish, highlight his inability to reconcile his past with his present. He reveals his profound sense of loss, expressing that the pain of Catherine's absence is unbearable, and he often talks to her as if she were still alive, illustrating his desperation and unresolved grief.

Heathcliff's fixation on Catherine leads him to reflect on their shared history, recalling joyful moments and the passionate bond they once shared. Yet, these memories are tainted by the betrayal he feels due to her marriage to Edgar Linton. The chapter deepens the exploration of Heathcliff's character, showcasing him not merely as a vengeful figure but as a profoundly wounded soul, trapped in a cycle of longing and resentment.

As the chapter progresses, the theme of hauntings becomes more pronounced. Heathcliff is haunted not just by the memory of Catherine but also by the consequences of his actions and the cycle of revenge that has ensued since her death. His interactions with other characters, such as Cathy and Hareton, are laced with the shadows of the past, reinforcing the idea that the legacy of love and pain continues to impact the present generation.

In conclusion, Chapter 15 encapsulates the essence of Heathcliff's character, revealing the depths of his torment and the ghosts that haunt him—both literal and metaphorical. It portrays his struggle with unresolved feelings towards Catherine and the weight of their shared history, emphasizing the novel's central themes of love, loss, and the inescapable grip of the past on the present.