Greta Nissen stars as an Italian noblewoman living a dangerous double life as a spy. A remake of the celebrated German thriller Spione am Werk. Co-starring noted German actor Karl Ludwig Diehl and American matinee idol Don Alvarado. The film takes place in Vienna, 1912. When an Austrian staff officer is implicated by association with a known Italian spy he goes on the run. Three years later – as the Great War gets into full swing – he returns and begs the Austrian Secret Service to allow him to clear his name from suspicion.