Handsome Dr. Henry Jekyll (March) seems to have everything going for him: he's a successful scientist respected by his peers, his charity work is rewarding, and his engagement to charming fiancée Muriel (Hobart) is right on track.

But Jekyll gets jeers when he publicly theorizes that man is composed of two halves intertwined: a good side guided by logic, morality and reason, and an evil side driven by primitive emotion and passionate carnality.

To prove his wild ideas, Jekyll develops a serum which he hopes will separate these two sides of man into distinct personalities.

Testing it on himself, he's ecstatic when it works!

Soon, Jekyll is transformed into the ape-like savage 'Mr. Hyde,' who terrorizes the streets of London and keeps dance hall maiden Ivy (Hopkins) prisoner as his sex slave.

Things get worse when Jekyll realizes he can't control which will be his dominant half...and it looks like the malevolent Hyde is determined to stick around!

Nicely photographed by Karl Struss (who lensed the 1920 silent version of Hyde starring John Barrymore), this is well paced and boasts a number of intriguing touches, like the subjective point of view opening and the tension-filled scenes with Ivy and Jekyll.

March won an Oscar for his powerful double performance here - and deservedly so - but Hopkins is equally good as the object of Jekyll's desire...and of Hyde's torture.

Remade in 1941 with Spencer Tracy and Ingrid Bergman.