The Unknown Quantity

Muriel Flemming secretly marries Graydon Burton before he heads West to make his fortune. Later, when he is about to board a train to return to his wife, he is accused of a murder that was actually committed by crooked attorney Herman Slade.

Orphaned after the death of their mother, Nancy Grimm and her baby sister Ellen are taken to the country where Ellen is adopted by the wealthy Walsh family. Nancy keenly feels the loss of her sister, and when the judge rules that she cannot visit Ellen without permission, she throws herself onto a bench, winning the sympathy of young attorney Chester Noble. Nancy is then placed in the Wick's home where she is treated as a servant. Miserable, Nancy cuts off her hair and, dressed as a boy, runs away.

Framed by police inspector Finch and his managing editor, R. H. Steadman, to cover up their own crooked work, reporter John Mull languishes in prison until he escapes, determined to wreak vengeance.

A poor shopgirl is offered a "good time" for a week by the son of her employer. She accepts, but the offer is misunderstood by her brother, who informs the girl's parents of her "fling."

When Marie Louise, the daughter of the town factor, returns home from school, Julio Sandoval, a reckless young half-breed ruled by his animal instincts, develops a passion for the girl, even though she is engaged to Captain McKeever of the mounted police. Meeting Marie when she is alone in the woods one day, the half-breed carries her to his cabin on the mountain top where he collapses from an attack of mountain fever brought on by overexertion.

Louis and August Siever, the twins sons of a German father and American mother, are traveling in Europe when war breaks out. August joins the Kaiser's army, but Louis, a supporter of the United States, is practically made a prisoner in Berlin for a year while he tries to prove his American citizenship. After a violent confrontation with Louis, August steals his brother's passport and leaves for New York with Gerda Anderson, a German spy.

Little orphaned Kate lives happily in a New England lighthouse with its old keepers, Philemon, Peter and Captain Bartholomew. When Kate falls sick, the prudish Philemon hires Miss Summerville, a live-in nurse, to care for her, but is concerned about possible gossip. To alleviate the situation, each keeper and Dr. Carlyle propose to Miss Summerville, but she rejects them all. After hearing that Captain Peyton, a lighthouse inspector, is scheduled to arrive, Miss Summerville makes sudden plans to depart without explanation. At the urging of Carlyle, she agrees to stay, but tries to avoid Peyton by turning off the lighthouse beacon.

After Fred, an orphan raised by his wealthy Uncle Oliver marries Clara over his uncle's objections, the two men become estranged. When Fred and Clara's child Paul is six years old, Fred insists that his uncle pay them a visit over Christmas. Uncle Oliver, a very lonely old man, begrudgingly accepts but refuses to behave amicably towards Clara or Paul.

During World War I, John Bowman, the captain of a tramp steamer, refuses to allow his wife and daughter Shirley to accompany him on a long voyage because he fears that the ship may be torpedoed. Before his departure, he entrusts his life insurance policy to shipping agent Sam Bullard, who, unknown to John, once courted Mrs. Bowman. Shirley, a clairvoyant, has a vision in which her father's ship is torpedoed, and the next day, Sam reports that the ship has been sunk and John killed.

Upon seeing millionaire Lee Brooks's picture in the paper, Julie Le Fabrier, a romantic young model in Madame Swan's dress shop, immediately falls in love with him. Soon afterwards, Julie is sent to the Grand Tides Hotel to deliver a dress to Madame Ricardo, an attractive young woman whose bills are paid by Lee's lovestruck father, Mason Brooks. Having seen her husband, whom she believed to be in South America, on the grounds, Madame Ricardo deserts the hotel, so Julie dons the gown and masquerades as Mason's mistress.

Angela, a lovely young woman of eighteen, lives with her grandmother in Virginia but knows very little about her mother, Lady Eldone, who after the death of Angela's father, moved to Europe and married an English army captain. When Captain Eldone is reported dead, Lady Eldone returns to the United States determined to marry a wealthy man.

Newly elected police court judge John Fairbrother is impassioned when it comes to the laws affecting the dives and cabarets of the city, and promises equal justice for all.

Phyllis Narcissa, an underpaid children's librarian, eagerly accepts a dinner invitation from Horace de Guenther, one of her patrons, and happily entertains his invalid wife. Later, Mrs. de Guenther encourages Phyllis to meet with Mrs. Harrington, a dying rich woman whose son Allan, once a vigorous young man, was paralyzed in an auto accident. When Mrs. Harrington proposes to the librarian that she marry and take care of Allan in exchange for his wealth, Phyllis reluctantly consents. While struggling to cheer up the eternally gloomy Allan, Phyllis welcomes the visits of his friend, a doctor who informs her that her husband's paralysis may be psychosomatic.

Inconsiderate millionaire John Benson, philanthropist Oliver North, courageous Langdon Crane, wealthy idler Robert Curtis and Lydia Benson are among the passengers on an ocean liner that is sunk by a German submarine. Carried away by the currents to a tropical island, the castaways endure hardships which bring out their true natures.

When young inventor Bob Moore fails in his efforts to provide his father, a safe manufacturer, with a lock that is burglar proof, he contacts The "Eel," the most talented safecracker in the city, to offer him a job in his factory. The Eel, deciding to go straight, accepts the offer, but when he later learns that Irene Hardin has been given a valuable necklace by her father, The Eel plans one last job to secure Irene's pearls.

Mrs. Standing, an old-fashioned country mother, sacrifices to put her son John through college so that he might have a better life. Upon completing school, John goes to the city where his financial success blinds him to the basic values taught to him by his mother.

While waiting in a hotel lobby for instructions from his government, Ludwig Schumann, an agent of the Black Legion, is enchanted by Marion Washburn, the daughter of a Texas senator. As he is about to speak to the girl, Schumann is stunned to see a young American enter who could be his double. The American is James Walbert, whom Schumann's contact mistakes for the agent. The contact passes to Walbert a photograph of a woman spy, Wanda Bartell, whom the agent is to meet aboard a steamer. Walbert realizes the mistake and determines to protect his country.

In dire financial straits, businessman John Baird considers liquidating the bonds that are held in trust for his little daughter Margery. Failing to comprehend her husband's desperation, Virginia Baird refuses his request and, upon overhearing his lawyer advising him to utilize the bonds without consulting her, she decides to place them in the hands of George Drake, an old friend. Drake hijacks the securities, however, and their disappearance leads to the break up of the Baird's marriage, resulting in Virginia leaving the house. Attempting to console her father, Margery sets out on her pony to bring her mother home. But she is held up on the road by Captain Kidd Jr., who adopts her as his first mate, and the two children take up residence on a grass hut on a nearby island.

Nancy Glenn is a pupil in Pop Hogland's school for crooks. When, attired as a boy named "Spider", Nancy fails at her lessons as a pickpocket, Pop decides to pair her with Pliny Drew, a graduate thief and swindler.

During a raging storm, a baby is washed up on shore on an island in Greece and is adopted by the wealthy Stanhopes, who name her Lorelei. Eighteen years later, Lorelei, now a woman, invites her school friends to spend their vacation at her villa. One of her guests, Julie, is insanely jealous of Lorelei. One day Gerald Waldron, a disenchanted society fop, sails by on his yacht, accompanied by his social-climbing friend, Hartley Royce. Seeing Lorelei and her friends swimming, they decide to go ashore. Both Gerald and Hartley fall in love with Lorelei, and Julie rages, finding herself relegated to Hartley. Together Hartley and Julie plot to separate the lovers.