The Lost Face.

A clearly confused girl is found wandering around Stuttgart and can't be understood, because she's speaking in a foreign language. The police take her to some doctors, who eventually believe they're dealing with a Tibetan. Doctor von Aldenhoff takes the stranger in and begins to educate her according to western European standards. In her new home, the girl, Luscha, gets to know Robert Lorm, a rather well-travelled man, and falls in love with him. Eventually, she decides quite unilaterally that they're going to build a new home and life together. A plaster of paris mask of the girl's face is made for the doctors to keep as a remembrance of Luscha. But as soon as the mold is removed from her face, she suddenly seems to become an entirely different woman.