The Highest Trump (1919)

"Richard Paget braves death as a traitor at hands of a girl he loves to expiate wrongs done to country by his dead brother- duty seals lips when one word might have absolved him."

Secret Service officer Richard Paget receives a letter from his twin brother John imploring him to take over his identity after he commits suicide, so that Richard can subvert the plans made by the airplane company which John had financed, to make defective planes for the United States to use in the war.