Desc: The Mainspring: Directed by Jack Conway. With Ben F. Wilson, Wilbur Higby, Henry Holland, Francelia Billington. Great financier Jesse Craven is ill, but so closely guarded that the public can obtain no details. Lawrence Ashmore, a young reporter, is detailed by his paper to obtain an interview. Larry Craven, Jesse's son, is expected one morning, and the chauffeur mistakes Ashmore for him. But when Jesse's niece Edith and friend Richard Creelman see Ashmore, they realize that he is not Larry and take him prisoner, fearing that he's a reporter. Larry has been kidnapped by the orders of Shackleton, who is the confidential man, also the former secretary to Craven, to Farnum and Sharp, two brokers who are bent upon the ruin of Craven and the thousands of stockholders who have entrusted their investments to him. Creelman and Ramsdale, Craven's broker, offer Ashmore a large sum of money if he will pose as Larry, and he agrees. He and Edith become friends. Farnum and Sharp, thinking they have Larry safe, manipulate the stock market, and things are looking rather serious for the Craven interests. In order to carry out their bluff further, it is planned that it shall be reported that Larry, in reality Ashmore, and a party will take a yachting cruise. Ashmore and the party leave on the trip, and Shackleton, who has secured the services of a chauffeur of the Craven's, kidnaps Ashmore, having enticed him from his own yacht by a ruse, and takes them on board their vessel. A storm comes up and the boat springs a leak. All are forced to jump overboard. Ashmore reaches the shore more dead than alive; Edith and the others think that Ashmore has deserted them at the crisis. Ramsdale and Creelman decide to give their entire fortunes to trying to save Craven interests. Craven is better, but Larry has control of his account, and he is helpless. Ashmore hails a passing car to take him back to the Craven place. He rushes to the Stock Exchange and turns the tide against the conspirators. The Craven fortune is saved. Farnum threatens to have Ashmore arrested for impersonating a member of the Stock Exchange. Ashmore defies him and tells him that he is the son of the man whom Farnum ruined, and that he possesses evidence which will send his enemy to jail. Farnum sees himself defeated at every turn. In the meantime Larry has caught Bernice trying to drug him and has managed to escape from her apartment. He hurries to the Cravens and is recognized at once as the real Larry Craven. He arrives just in time to prevent the shooting of Ashmore by Farnum. Ashmore is presented to Larry as the man who saved the Craven fortune. Larry sees that Edith and he are in love and offers him the position of manager of the Craven interests, which Ashmore accepts. Soon after, Edith accepts him as her life partner.