A story told, staged or written within the work itself, which mirrors or comments on the main story.
In The Brothers Karamazov
there are three forces, the only three forces on earth capable of conquering and holding forever the conscience of these weak rebels, for their happiness: these forces are the miracle, the mystery and the authority.
The line comes from a poem that Ivan invented and tells his brother in the tavern. The Inquisitor's speech is, therefore, a story within the conversation of the two, and reveals what Ivan thinks without his having to assume it.
Book V: Pro and Contra, the Grand Inquisitor to the prisoner, in Ivan's poem
he suddenly approaches the old man in silence and gently kisses his bloodless lips of ninety years. That is the whole answer.
Book V: Pro and Contra, Ivan to Alyosha, on the poem's ending
Once there was a wicked, wicked woman, and she died. And not a single virtue remained of her. [...] she, he says, pulled an onion out of the vegetable garden and gave it to a beggar. [...] The moment she said it, the onion broke. And the woman fell into the lake and burns to this day. And the angel wept and went away.
Book VII: Alyosha, Grushenka to Alyosha, at her house
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