This visualization displays the progression of COVID-19 cases across multiple Chinese provinces from January to February 2020. It animates line curves for each province, showing the count of existing confirmed cases over time, with provinces added sequentially. The code uses D3 v6 with a time-scale for the x-axis and a reversed linear scale for the y-axis, rendering SVG paths with cardinal spline curves. Data is loaded from a CSV file, and each province’s line is animated into place using d3 transitions over two seconds.