Smashing Through (1918)

Claim jumper Dave Marco and his boss Earl Foster, a crooked investment broker, hire chemist Ralph Brandon to falsify papers that a certain worthless mine is valuable then convince Ralph's mother to invest all her money in the mine. Ralph’s sister Holly meets Jack Mason, whose mine is actually valuable though not yet profitable, and they fall for each other. Once Mrs. Brandon finds out she has been duped, though forced into silence by the threat of having Ralph’s malfeasance exposed, and Marco attempts to jump Jack’s claim events come to a head until the happy conclusion.