The fears of the Empire have come to pass. The sleeping Shadowlands have awakened, and its undead forces are spreading their darkness across the face of Rokugan. The Clans have joined forces with the Naga to repel the invaders. And while the defenders of Rokugan have turned their attentions to the south, the Scorpion Clan - thought to have been destroyed by the Emperor - has returned with a plan of vengeance that will bring the Empire to its knees.
-from the Shadowlands box