Tolstoy presents a brief flashback in a scene in which Princess Marya Bolkonsky suddenly recalls a moment from the past upon hearing of the apparent death in battle of her brother, Prince Andrei:
The princess sank strengthlessly into the armchair next to her father and wept. She now saw her brother at the moment when he had taken leave of her and Liza, with his tender and at the same time arrogant air, saw him at the moment when, tenderly and mockingly, he had put on the little icon. “Did he believe? Did he repent of his unbelief? Was he now there? There, in the place of eternal rest and bliss?” she wondered.
Distraught upon receiving the news that her brother was likely killed in action, Princess Marya "sank strengthlessly into the armchair next to her father and wept." Suddenly, she vividly recalls a memory as if it were occurring in front of her. Before Prince Andrei left for war with France, saying farewell to his sister and pregnant wife with a "tender and [...] arrogant air," Princess Marya forced him to accept a small religious icon, which she intended for his protection. In response to her entreaties, he "put on the little icon," she remembers, in a loving but also mocking manner. After this brief flashback, she wonders whether or not Prince Andrei, who expressed little interest in religion, came to "believe" in God or "repent" of his disbelief. For the pious Marya, the answers to these questions have serious spiritual consequences, and it's no surprise that they would occur to her now, when she fears for her brother's life.
In a military hospital, a deeply injured Prince Andrei sees a man whose leg has been amputated and realizes, with surprise, that he recognizes the man. Here, Tolstoy employs a flashback to clarify the identity of the injured soldier:
“What is this man’s connection with my childhood, with my life?” [Prince Andrei] asked himself, without finding an answer. And suddenly a new and unexpected memory from the world of childhood, purity, and love came to Prince Andrei. He remembered Natasha as he had seen her for the first time at the ball in 1810, with her slender neck and arms, with her frightened, happy face ready for rapture, and in his soul love and tenderness for her awakened, stronger and more alive than ever. He now remembered the connection between him and this man [...]
As he stares at the man, he is suddenly struck with a "new and unexpected memory from the world of childhood," which is presented in the form of a brief flashback. When he sees the man, he suddenly thinks of Natasha "as he had seen her for the first time at the ball in 1810." He describes her as though he can see the scene directly in front of him, noting her "slender neck and arms" and her "frightened, happy face." Suddenly, he is overwhelmed with love for her, despite the bad terms upon which they ended their engagement.
Feeling "in his soul love and tenderness," he recognizes the man as Anatole Kuragin, whose bigamous attempt to elope with Natasha put a swift and humiliating end to Prince Andrei's own engagement with her. Though, earlier, he attempted to find Anatole in the hopes of provoking the man into challenging him to a duel, Prince Andrei is no longer able to carry hate for others. He not only forgives Anatole in his own mind, but resolves to love his enemy as well, marking his final acceptance of "Christian" or universal love.