Source: http://www.novelguide.com/the-real-life-sebastian-knight/summeries/chap19-20
Timestamp: 2019-04-25 05:47:59+00:00

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Sebastian last tried to see Nina in the spring of 1935, but she had him turned out by some ruffians. He returned to London as his last book came out and appeared in public though he was thin and ill. He almost met Clare then, but as fate would have it, he just missed her because of Miss Pratt. He was on his way to a bookstore to get something, while a moment before Clare had entered that same bookstore to buy his book. Miss Pratt came out and saw Sebastian, and they chatted while he walked her to the underground station. She was happy to help them avoid one another.
Sheldon saw him once at his club, and then Sebastian disappeared. In January of 1936, when V. was in Marseilles, he got a letter from Sebastian saying he was in Paris. It was his last letter to V.. He says he has changed, and once scornful of the ordinary, now finds solace in it. He would like to meet V. and talk about real things, their lives, for instance. He asks V. to burn his letters. He had started this letter to a different person (presumably Nina) but now he addresses it to V.. He is in a sanitarium outside Paris. He wants V. to come there.
V. sees that Sebastian is not well but does not realize he is dying. He resolves to go on the weekend. Meanwhile he has a terrible nightmare about waiting with his mother for Sebastian. When Sebastian arrives he is wearing a black glove. V. is terrified of being touched with this dead hand. Then Sebastian vanishes but he continues to hear his voice saying something important to him. When V. awakens, he receives a telegram from Sebastian's doctor saying his brother is hopeless, and he needs to come right away.
The rest of the story could be a continuation of the nightmare, for V. rushes to the train and forgets to take the address of the sanitarium. He is terrified he will not get there in time, and even prays. He feels he will get an extraordinary revelation from his brother. The train is late; V. has to go to his office in Paris to get enough money to get to the sanitarium; he can't reach the doctor. He sees scratched on a wall the moves of a chess game and the word, damier (chess board). He remembers the name of the sanitarium is St. Damier's. He takes a cab, and finally a carriage, getting to the sanitarium in the dark. He asks for his brother, and the clerk tells him a man died last night. Sebastian is stricken, but then the clerk says no, it is Room 36. The nurse says he is alseep, so V. sits by the bed in the dark. He hears the breathing of the patient, and feels happy he is alive. V. falls into a sense of security and a wave of love. He does not know how they drifted apart. He cannot tell his own breathing from his brother's. Finally he finds out from the nurse that this is not his brother; his brother was the man who died last night.
Instead of being depressed, V. feels the last moments of hearing the man's breath changed his life as though it had been his brother. What he learned was what Sebastian would have told him: “the soul is but a manner of being—not a constant state—that any soul may be yours, if you find and follow its undulations . . .” (Chpt. 20, p. 204). V. concludes by telling the reader if this is true, then, since he has followed Sebastian's soul so closely, “Thus—I am Sebastian Knight” (Chpt. 20, p. 205).V. has been vicariously acting Sebastian's part, with the other characters coming and going on the stage, but he cannot take off the mask at the end of the story. Sebastian and V. have become the same consciousness writing this biography.
As in the rest of the story, there are missed and chance meetings. Miss Pratt interferes with Sebastian's last possible meeting with Clare. They were two wavy lines coming together again, but kept apart by something trivial. Presumably Miss Pratt is protecting her friend. Sebastian had described these sorts of moves in his novels. V. wonders what kept him from his brother all those years, the one mind he could understand? He makes a desperate dash to be there at his brother's deathbed, but spends time at another man's deathbed, missing Sebastian's departure. It seems fate rules. There is no way he could have gotten there on time.
One expects a depressing ending, but V. gets his revelation after all. He says it is what Sebastian would have wanted him to know. With enough consciousness, one might live in any other soul by following out its delicate moves. Thus V., who followed his brother so faithfully in his writing and in his life, using his imagination to piece out Sebastian's inner experience, can completely identify with him. Or, perhaps, he suggests, he is Sebastian, writing this account from the perspective of a witness of his own life. The ambiguity of the ending and the identity of V./Sebastian is characteristic of Nabokov's love of puzzles and language play. Commentators find endless interpretations in every sentence and paragraph.
In spite of puzzles and ambiguity, Nabokov's writing is full of the beauty of expression and human feeling and the mystery of human identity.

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