The Mask (1921)

Kenneth Traynor goes to South Africa to investigate conditions in a diamond mine in which he is interested. He is about to return home when he meets his wayward twin brother Jack, who starts home with him. The ship is blown up and everyone reported lost. Signor Keralio, a friend of Kenneth Traynor's, suddenly surprises Kenneth's wife with the news that her husband has been saved. In reality it is Jack Traynor. He has conspired with Keralio to impersonate his brother, for which Keralio agrees to pay him well, Keralio's purpose being to secure Kenneth's wife for himself. Eventually the real Kenneth returns, but is demented. He visits his home and is recognized by his son Mickey. Keralio sees Kenneth with the boy and brings them both to his apartment, then sends for Mrs. Traynor and gives her a glimpse of her real husband and boy. He is forcing his attentions upon the wife when Kenneth suddenly becomes his normal self, recognizes his son, and rushes to his wife's rescue.