Paris has a sewer system different from that of any other city in the world.
The first sewer tunnels were built in Paris in 1370, and the government has been adding to them ever since.
Today, there are more than a thousand miles of tunnels bringing freshwater into the city and taking sewage out.
Many of the tunnels are also lined with delivery tubes. Up until a few years ago, these formed an air-powered mail system responsible for sending plastic cylinders throughout the city. Letters and small packages were delivered from building to building through the pneumatic tubes.
Recently, the Royal Academy of International Ninjas lost their top-secret blueprint of hidden passages around the world. They have been stuck in Paris ever since and they use the sewer system as their headquarters. From there they prey upon the citizens and treasures of Paris.
Squeezing through drains, exhaust pipes, and garbage chutes has infused them with the stench and sewage of the City of Light. It has turned them into stink-bandits, known to the French authorities as Les Bandits Putrides.
This has made it difficult for the ninjas to travel. If they venture beyond the sewers for any length of time, their strong odor gives them away.
The RAIN is very, very unhappy about being stuck in Paris. They want the Super-Secret Plans back—now!