Evil begets evil, or victims become perpetrators.
A story published in Dostoyevsky’s magazine, adapted into an opera, further tweaked and truncated to this.
Some upper class lady is brutally treated by her husband and father-in-law, until left alone, bored out of her wits. Walking about in nature is not enough, so she picks some boy to horse around, overtly.
When the father in law returns to discipline her and the boy, she just kills him, discretely. Her handmaiden is frightened by this, and goes mute for ever. More hanky-panky with the boy ensues.
Eventually, the talk reaches her husband, who arrives at night for a thrashing of epic proportions. He doesn’t care about his father either, but does care about whoring. After provocative fucking her boy in front of the husband, she kills the husband too, and his horse. Her boy is frightened by this, and he remains hidden.
Out of nowhere comes a nanny with a kid, saying she has papers proving her husband had this kid and is fostering him. The Lady abides, but against her will, since she has a child of her own on the way. The kid is pretty much left to his own devices, but he is stopping the Lady from being with her boy. Yup, you guessed it, she smothers the kid. Her boy is frightened by this, and wants nothing to do with her now.
A small investigation is needed, since there are bruises in the kid. Her boy confesses the crime, it is weighing too heavy on him. The Lady makes up another story from incidental evidence, and throws the mute maid with him to the gallows.
In the end, she is bored in the empty house, again.