 Riccado d Arce, a righteous knight, is the secret friend of Ciro, duke Di Pallanzo s son and the secret fiancé of his beautiful sister Bianca. On the other hand a faithless knight, count Fosco Di Villabruna, covets both the duchy and Bianca, and soon becomes Riccardo s sworn enemy. Fosco has Ciro murdered and Riccardo accused of the crime but ... he laughs longest who laughs last!