A force-directed network graph visualizes the relationships between characters from Les Misérables, with nodes colored by their categorical group (Document, Email, Person, Location, etc.). The simulation uses `d3.forceSimulation` with `d3.forceLink`, `d3.forceManyBody`, and `d3.forceCenter` to position nodes, while SVG circles and lines render the graph. A color legend generated via `colorLegend` maps group categories to `d3.scaleOrdinal` colors. Data is loaded from a JSON file.