Silent film about Darwin's evolution theory

A detective falls for a Japanese girl living with her uncle and cousin. When the girl's uncle is murdered, the detective must find out who killed him.

James Mistoll, one of the owners of a factory, and working on a process to turn copper ore into radium, falls from a window on the fourth floor and dies; This was no accident, but a murder. A detective sends his assistant, Barnes, to investigate and soon the number of suspects from within the company multiplies.