Rudolf Diesel invented the most efficient internal combustion engine ever designed and then disappeared from a cross-Channel steamer in 1913. His body was found floating in the North Sea. Whether he jumped, fell, or was pushed remains one of the great unsolved mysteries of the industrial age.

This episode traces Diesel from his Parisian childhood through the engine development, the financial troubles, and the mysterious disappearance from the SS Dresden.

• The thermodynamic theory behind the diesel engine
• The years of development, explosions, and the working prototype
• The financial overextension and mounting debts
• The disappearance and competing theories — suicide, murder, or accident