Rise of the Ninja by Simon Higgins

In the moonlight, the explosive fast draw became a horizontal streak of silver, flashing momentarily from the cover of the shadow. The tip of Moonshadow's sword ambushed the lurking foe, who stood, still drawing his own weapon. It's the dawn of an age of peace in medieval Japan, and a power hungry warlord is plotting to plunge the nation into a deadly civil war using a secret weapon from the West. Enter Moonshadow, the newest and youngest agent for the Grey Light Order, a covert brotherhood of shinobi (ninja spy warriors) who work for the shogun. For his first mission, Moonshadow is sent on a perilous journey to capture the plans for the secret weapon. Can Moonshadow defeat the evil warlord, rogue samurai, professional killers, and another ninja spy to save his country from violent chaos? Or will his first mission also be his last?

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