Both films of season 4 premiered in theaters.
The book Gunvald has that Kim Reeshuag left at the diner is titled "Slouching Toward Bethlehem" by American writer Joan Didion. The book is 1968 collection of essays by Didion that mainly describes her experiences in California during the 1960s. The title essay describes Didion's impressions of the Haight-Ashbury district of San Francisco during the neighborhood's heyday as a countercultural center. In contrast to the more utopian image of the milieu promoted by counterculture sympathizers. One critic describes the essay as "a devastating depiction of the aimless lives of the disaffected and incoherent young."