The Web of Chance (1919)

Dorothy Hale, the niece and secretary of detective agency head John Harrison, meets Arthur Brown while on vacation with her uncle. Arthur falls in love with Dorothy, but business affairs force him to leave abruptly. Back in the city, Harrison investigates the theft of a million dollar contract stolen from the private files of the Sarsfield Company. Supposed employee Arthur Brown is a leading suspect, and Dorothy takes it upon herself to shadow him using various disguises. After a series of chases and escapades, it develops that Brown is actually Arthur Brown Sarsfield, the head of the contracting company, who assumed the false name to fulfill certain conditions of his father's will. The real criminal is apprehended, and Dorothy and Arthur are married at once.