The Best Man (1919)

An international gang of crooks, the Holmans, steal a coded paper and send for their London agent, John Burnham, to come to New York to decipher it, but Cyril Gordon, a United States Secret Service agent, impersonates Burnham and retrieves the paper. A taxi meant for Burnham takes Gordon to a church where a George Hayne, Burnham's real identity, is to marry Celia Hathaway, who has not seen Hayne in 15 years. Remembering that he is to "stop at nothing" to save the code, Gordon marries the rich, pretty Celia and leaves with her on a honeymoon train through Pennsylvania, followed by one of the crooks. Celia berates Gordon for blackmailing her into marriage, but is pleasantly surprised by his character. After some adventures escaping from the crooks, they genuinely fall in love. In Washington, the code is delivered and the thieves captured. After Gordon reveals his secret, the couple acknowledges their desire to stay married.