The family drama in The Girl with the Dragon Tattoo takes on soap-opera proportions. The Vanger family is super wealthy and influential but, as Blomkvist soon learns, also "clearly dysfunctional" (9.138). To find out why and how Harriet Vanger disappeared in 1966, 36 years prior, Blomkvist and Salander have to comb through one hundred years of Vanger family history, Nazis and all. And what they uncover is not pretty.
But, the Vanger family isn't where the discussion on family stops. Blomkvist has unconventional views on family, and finds more success in friendships with benefits than married with children. For example, his relationship with his teen daughter is a problem area for him. Salander's family is largely mysterious, though we learn a tiny bit about her mother and sister. Salander's family history is a focal point of the next installments of the trilogy.