Lola and Valasquez, to adventurers, are sorely in need of funds. They chance to meet Archibald Rivers, a banker, in a café one night, and begin to weave their web about him. Rivers has been entrusted with the care of Mary Harrison, an orphan. He is trustee of the fortune left her by her father. Mary has come to live in Rivers’ house. She meets Donald, his stepson, and the seeds of love soon take root in the young folks. Mrs. Rivers is taken up entirely by her social duties. Her lack of interest in her home and husband causes Rivers to fall an easy prey to the wiles of Lola. Soon we find him enthralled by her, lavishing gifts upon her and satisfying her every wish. During all this time Rivers has been suffering severe financial reverses and on many occasions has been employing Mary’s money to help him in his own business. Lola, meanwhile, has been inflamed with a passionate longing for Rivers. She wants him as her own, unmolested by any others. She has been reading of the crimes of the Borgias, and her fiendish mind evolves a plan to get Mrs. Rivers out of her way. One evening, as Mrs. Rivers gives a masque ball at her home, Lola, disguised by her long domino and mask, enters the ball room. She has prepared the fatal ring with its prong dipped in the venom of a Cobra snake. It takes but a moment and Mrs. Rivers is dead. Donald is determined to root out the mystery. Rivers, whose speculations have caused him to lose Mary’s fortune, sees that his only chance to escape from punishment lies in his marriage to her. But Lola is firm. With Mrs. Rivers out of the way, Rivers must belong to her only. Donald, however, has labored ceaselessly, and his efforts have determined Lola as the murderess of his mother. But Fate has decided to become mistress of the situation. The drama shall be ended as she decrees. Valasquez, whom Lola has discarded for Rivers, kills his rival in a jealous rage. Lola has but one course left; she turns her weapon against herself, and as the Cobra’s poison rushes through her veins, she falls across the body of Rivers. In the web she wove for the fly, the spider found her own undoing. Donald and Mary are left alone. Together they will strive to recover her fortune, and to spend their days, wrapped in a love as powerful and unfailing as the Cobra’s venom in the Borgias ring.