Complex sentence: Robert is haunted by dreams that seem to tell the future as well as the past; his life changes when a storyteller invites some of his class to Mayfield House, a place Robert has already dreamed about.
Split into simpler sentences: Robert is haunted by dreams that seem to tell the future as well as the past. His life changes when a storyteller invites some of his class to Mayfield House, a place Robert has already dreamed about.