Innovative professor of science, Dr Jekyll, theorises that the primordial aggressive elements of a personality can be physically separated (and ultimately eliminated) from the benevolent nature that has superseded it through evolutionary development. On a domestic level he is happily expecting to marry the love of his life but his aspirations (and sexual desires) are thrown into disarray as her father continues to postpone approval of their impending marriage. Immersing himself in his work he decides to test his theories by consuming the chemical formula he has developed that is intended to initiate the separation. It does the trick but not in the way he was hoping: a transformation occurs that gives birth to a manifestation of his darker side. Referring to himself as Mr Hyde, this almost Neanderthal incarnation of his inner being goes about making a general nuisance of himself until he begins to form a relationship of sorts with a prostitute that Jekyll helped out earlier, a situation that the girl is too scared to end or escape from due to the escalating horrific behaviour with which Hyde conducts himself. Not realising that Hyde is the alter-ego of Jekyll she goes to visit the (oblivious?) good doctor for help again, at which point he realises what terror Hyde has caused and promises the traumatised woman that she will never see the monster again, determined himself to now leave alone the potion of his own creation. But Jekyll fails to anticipate that the formula has mixed inextricably with his blood and the transformation is no longer within his control.
Packaged with the 1941 version of the same story the UK Region 2 Warner disc is excellent value for money. The 1931 film itself, presented 1.33:1 B&W, looks as beautiful as you can expect. Problematic censorship history notwithstanding (footage excised from older films has often been difficult to re-obtain) I also believe that it’s complete at 92 minutes (PAL, running 25 fps) - in British cinemas back in the 30s it only ran for 81 minutes! As a vintage chiller of great worth it’s up there with Universal's Frankenstein and Dracula.