The Blight narrative arc is comprised of five Nyrond and Her Environs Meta-Regional adventures, played in seasons five and six. While they can be used separately with some adaptation and assumptions, the narrative plot of the modules forms a continuous story.
NMR5-01 Under the Boughs
NMR5-02 Natural Enemies
NMR5-04 Charity of Friends
NMR5-07 Corruption of the Heart
NMR6-01 The Blighted Star
This series should not be confused with the similarly named and much more widely circulated Blight on Bright Sands, another Living Greyhawk Core narrative arc also played during seasons 5 and 6.