British International Pictures,the producers of this film were at the forefront of sound films in the UK.They made "Blackmail".They turned their silent films into part talkies by adding sound to the second half.So it is a bit of a puzzle as to what happened here.Whenever there is an exterior,parts or all of the dialogue are not recorded,there is just music.There are no subtitles ,so you don't know what is happening.It would appear that the principal actors came from the opera stage and therefore they act in the most theatrical way throughout the film.However the sword fights seem to be acted out in slow motion.In any event even if you are an enthusiast for early talkies,you will find it difficult to sit through this film unless that is you are a lover of the opera itself.I found the film virtually unwatchable.