What are the motifs in Laughter in the Dark by Vladimir Nabokov?

Concern is a recurring idea. Concern is a commodity in short supply in Vladimir Nabokov's Laughter in the Dark. Its epitome is Paul, Albert Albinus' hefty brother-in-law, who first sees signs of Albert's unfaithfulness and, when it is confirmed, takes in his sister Elisabeth and eight-year-old niece Irma, and significantly rearranges his comfortable lifestyle to accommodate them. Although he is angry enough at Albert to strike him—having never in his life hit another human being—Paul twice does Albert a good deed: first coming to his flat to fetch him to his daughter's deathbed when the phone line is constantly busy, and later, traveling to Switzerland to rescue him from imprisonment and exploitation at the hands of his unloving mistress, Margot Peters. Paul brings Albert back to Berlin, cleans him up, and endures his silence as a house guest.