In this only surviving episode of action-adventure serial Dr Sin Fang, Lt John Byrne and Bill Riggers are on the hunt for the criminal doctor, who is hell-bent on locating a lost ‘sacred seal’. A trader hoping to make a quick buck on the seal is lured to Fang’s lair, where he and Riggers are held prisoner in Fang’s torture cage. Only Byrne’s fiancée, Betty Harbray, can save the day.