The Ruling Passion (1922)

James Alden--machinist, designer, inventor, and multimillionaire who has given the world the "Alden" automobile engine--is ordered by his doctor to retire. Unable to remain idle on his country estate, Alden goes into partnership with young Merrick, and on the sly he works in a garage they open on a new state highway. Peterson, an unscrupulous business rival, loses trade because of his business methods; Alden and Merrick, on the other hand, attract customers by courtesy and consideration. Angie, Alden's daughter, discovers her father's subterfuge; but Merrick, whom Alden knows as John Grant, is in love with Angie. Her father gives his consent to their marriage and is revived by his "rest cure."