Part 5: Kostya and Kitty marry and start their new life on his country estate. Although the couple are happy, they undergo a bitter and stressful first three months of marriage. Kostya feels dissatisfied at the amount of time Kitty wants to spend with him and dwells on his inability to be as productive as he was as a bachelor. When the marriage starts to improve, Kostya learns that his brother, Nikolai, is dying of consumption. Kitty offers to accompany Kostya on his journey to see Nikolai and proves herself a great help in nursing Nikolai. Seeing his wife take charge of the situation in an infinitely more capable manner than he could have done himself without her, Kostya's love for Kitty grows. Kitty eventually learns that she is pregnant. Anna Karenina is a novel by the Russian author Leo Tolstoy, first published in book form in 1878. Many writers consider Anna Karenina the greatest work of literature ever, and Tolstoy himself called it his first true novel. It was initially released in serial installments from 1873 to 1877 in the periodical The Russian Messenger.