(Elements: Two Adulterers; a Betrayed Husband or Wife)
This, to my mind, is the only strongly appealing form in which adultery can be presented; otherwise is it not a mere species of house-breaking, the less heroic in that the Object of theft is an accomplice, and that the household door, already thrown open by treachery, requires not even a push of the shoulder ? Whereas this treachery becomes at least logical and endurable in so far as it is a genuinely sincere folly, impassioned enough to prefer assassination to dissimulation and a base sharing of love.
A (1)—The Slaying of a Husband by, or for, a Paramour:—the "Agamemnons" of Aeschylus, of Seneca and of Alfieri; Webster's "Vittoria Corombona"; "Pierre Pascal"; "Les Emigrants" (Hirsch, 1909); "L'Impasse" (Fread Amy, 1909); "Partage de Midi" (Paul Claudel); "Amour" (Leon Hennique, 1890); the beginning of the "Powers of Darkness." Historic example, with pride and shame as motives for the crime: the legend of Gyges and Candaules. From fiction: the first part of "Therese Raquin."
(2)—The Slaying of a Trusting Lover:—"Samson et Dalila" (opera by Saint-Saens, 1890.)
B—Slaying of a Wife for a Paramour, and in SelfInterest:—Seneca's "Octavia" and also Alfieri's; "La Lutte pour la Vie" by Daudet (in which cupidity dominates adultery); "The Schism of England " by Calderon; "Zobeide " by Gozzi. Narrative example: Bluebeard. Historic: the murder of Galeswinthe.
Hints for varying and modifying this situation:—
The betrayed husband or wife may be either more or less powerful, more or less sympathetic in character, than the slayer. The blindness of the intended victim may be more or less complete at various moments of the action; if it be dispelled, partly or fully, it may be by chance, by some imprudent act of the guilty ones, by a warning, etc.
Between the victim and the intruder, ties of affection, of duty, of gratitude, may 1 ave previously existed; ties very real to one or the other of the two. They may be relatives; they may find themselves united by some work or responsibility in common. The Victim, whether he be pursued openly or secretly, will be, doubtless, the object of an old rancor, either on the part of the consort or of the intruder; the origin of this rancor may be in any one of the imaginable offenses by which a human being is wounded in his family affections, his loves, his ideals, etc., or in his pride of birth, of name, of achievement; in his interests, (money, property, power, freedom); in any one of the external radiations of life.
Of the two adulterers, one may be but an instrument —impassioned or resigned, unconscious or involuntary —of the other, and may later be rejected, the end being attained; the blow may be struck by one of the two traitors alone, or it may be that neither of them has stained his own hands with the crime, which has been committed by a new character, perhaps unintentionally, or perhaps from love of one of the two Adulterers, who has utilized and directed this passion, or has let it move of its own accord toward the desired and criminal end.
A multitude of other characters will be, in varying degrees, the means employed, the obstacles, secondary victims, and accomplices in the sinister deed; the deed itself may be brought about according to the author's choice among the numberless circumstances which the Law has foreseen, with divers details such as court trials suggest.
If a more complicated action is desired, interweave (as Hennique has done) a rivalry of Kinsmen, an unnatural love (see Euripides' Chrysippe), an ambitious purpose and a conspiracy.
Adultery is a socially disapproved-of activity in most cultures and generally creates much sympathy for the betrayed.
Normal adultery can turn worse when the emotions aroused, including guilt, can lead an adulterer into even worse acts. When a person is already cast as bad and guilty, they may either believe the accusation and act in an evil way, or they may think 'In for a penny, in for a pound' and dispense with consideration of normal values.
Denial of the wrong-doing may also lead the person into argument and displacement of their bad deed onto the spouse, who pays the ultimate and terrible price.
The watcher of this story may hardly believe their eyes, yet know that this kind of thing does happen in reality as once-normal people sink into dark and evil acts. This is hardly the act of a hero, but may well give the hero something of a quest in bringing vengeance or justice to the murderer.