Desc: The Blue Envelope Mystery: Directed by Wilfrid North. With Lillian Walker, John Drew Bennett, Bob Hay, Charles Kent. Leslie Brennan, an heiress, suddenly discovers that she is almost penniless, and faces the ordeal of making her own living. Before learning this condition of affairs she had become dazzled by the society manners of a cold-hearted fortune hunter, but becomes disillusioned when she discovers that he is attracted solely by her supposed wealth, and goes at once to earn her livelihood in the City of New York. There she studies typing and makes friends among the lowly. She secures a position with a brusque preoccupied young chemist, who is in the midst of a great discovery of value to the government. How Leslie becomes aware of the machinations of a foreign spy, how she saves her young employer's secret to the government in a series of encounters and how she comes to learn that he has fallen in love with her and that he is one who is really worthy of her, is told in a series of compelling scenes.