A French nobleman (Wilde) is enlisted by a wealthy widow (Wallace) to retrieve a priceless star sapphire, Star of India (gem), that has been stolen from her jewel collection. He is aided by a Dutch spy, posing as a noblewoman, who has secret designs on the jewel. Both have to contend with the cunning villain (Lom) who stole the gem with the support of the French king, who also seeks to own the fabled jewel.