Driving away, Humbert notices that he is covered with Quilty's blood. Having committed murder, he decides to drive on the wrong side of the street. He gets out of the car and waits to get arrested.
He reflects on the sounds of children playing and feels profound guilt that he deprived Lolita of the simple pleasures of youthful innocence.
That is his story. It took him 56 days to write Lolita, which he started in the psychiatric ward.
He is opposed to capital punishment but thinks he should get 35 years in jail for rape.
He ends the book by addressing Lolita, hoping that she lives a decent life, treats her husband and child well and does not mourn the death of Quilty. The book he has written is their way to share immortality.