This is a bold film for its time because it tackles mental illness head on - in this case multiple personality syndrome. Thaxter is quite good as the sweet young girl occasionally taken over by the evil Karin (voiced brilliantly by Audrey Totter). Unfortunately the director takes it all far too seriously, and his constant cut-aways to grim or shocked reaction shots becomes comical. You really feel for the actors. Thank God for the wonderful Edmund Gwenn, who is the only actor who makes the material almost believable. And what a great psychiatrist he is - he can cure multiple personality syndrome in a matter of seconds, just by talking sternly to the evil side! Some nice visual moments and the uniqueness of the material make this film worth a look.