The Green Flame (1920)

Country bumpkin Frank Marham comes to New York City to work in a world-famous jewelry store. At the hotel where he lives, Frank meets Ruth Gardner, a newspaper reporter who is investigating the operations of a gang of jewel thieves, as is also her admirer, detective Dan Lantry. The store's manager, Roger Imlay, is a member of the gang which is planning to steal the famous emerald known as the "Green Flame," owned by the proprietor. Capitalizing on Frank's naïveté, Imlay tricks him into bringing the gem to the gang's headquarters, but Frank, actually a member of the Jeweler's Protective Association, surprises the crooks. At that moment, Lantry arrives and, mistaking Frank for the leader of the crooks, is about to arrest him when the owner of the store arrives and explains that he had hired Frank to watch Imlay. The mystery satisfactorily solved, Ruth and Frank fall into each other's arms.