Thomas Southerne finished "Cleomenes" for Dryden, with whom he was closely associated, and his tragedies follow Dryden's later work in maintaining the Elizabethan traditions of blank verse, comedy, double plots, shifting scenes, horrors, and persons of varied ranks. His "Loyal Brother" (1682) is wholly commonplace, and "The Spartan Dame" (1719) and "The Fate of Capua" (1700) do not depart from usual themes and methods, though the latter is in some respects Southerne's best play; but his two most successful plays, "The Fatal Marriage" (1694) and "Oroonoko" (1696), both based on novels by Mrs. Behn, present decided innovations in theme. "Oroonoko, or the Royal Slave" contains much comedy, and has little merit besides the novelty of the story, presenting the virtues of a negro slave. "The Fatal Marriage, or the Innocent Adultery" introduces the Enoch Arden story, attached to an outrageous comic underplot derived in part from Fletcher's "Nightwalker." In the main plot, Biron, oldest son of Baldwin, has been captured by pirates and is supposed to be dead, his letters being kept secret and answered by his villanous brother, Carlos, who urges his wife Isabella to marry. After Baldwin, instigated by Carlos, has thrust her out from his house, she accepts the devoted Villeroy. Biron returns; she goes mad in a scene of great imaginative power; Carlos and his assistants endeavor to kill Biron, who is rescued by the returning Villeroy. Biron, however, dies; and an accomplice of Carlos, tortured upon the rack (on the stage), confesses and exposes Carlos. Then "enter Isabella distracted, her little son running in before, being afraid of her." She stabs herself. Like Otway's "Orphan," this is virtually a domestic tragedy, for there are no interests of state or court, and our sympathy is centred solely on the innocent distress of the heroine. Like Otway, again, Southerne gains his greatest effects by an appeal to pity. The sentimentality that we attribute to the days of Richardson's "Clarissa" earlier triumphed on the stage in the heroines of Lee, Otway, and Southerne. Not less successful on the stage than the plays of Banks and Southerne was the single tragedy of Congreve. First acted in 1697, "The Mourning Bride" continued without alteration through the next century, and furnished Mrs. Siddons with one of her greatest parts. Congreve's remarkable dramatic ingenuity was skillfully exercised in combining all the elements that the average audience delighted in, and yet presenting these draped sufficiently to avoid offending the judicious. Classical form and technic permit a sensational and gruesome fifth act; dignified and facile verse gives way at times to outrageous rant; the usual plot of the rival ladies and rival lovers is ingeniously complicated to supply suspense, surprise, and a happy ending.