ROME — Roberto Saviano’s best-selling 2007 book, “Gomorrah,” his reportage about the Neapolitan crime syndicate the Camorra, was dark. Matteo Garrone’s award-winning 2009 film adaptation was darker. And the hit Italian television series of the same name is by far the darkest.

“Gomorrah” the TV show, which makes its United States debut on SundanceTV on Wednesday, Aug. 24, tells the story of a newly invented fictional crime family. And its depiction of a brutal underworld has broken new ground in Italy, where television tends toward sap and kitsch. It has also prompted a debate about whether it paints too sympathetic a picture of the criminals and too grim a picture of Naples (and Italy) at a time when grass-roots opposition to organized crime is thriving.

“There were two polemics about the series,” said Aldo Grasso, the television critic for Corriere della Sera, Italy’s leading daily. “The first is that it presents a bad image of Italy. The second is that it could be seen as a ‘bad teacher’ and that by watching the series a lot of young people might go to the other side.”

The show follows the drug-dealing Savastano clan after the arrest of its boss, Don Pietro, played with understated rage by Fortunato Cerlino, a veteran actor from Naples. Realizing that his teenage son and only heir, Genny (Salvatore Esposito), isn’t up to the job, he hands the reins to a trusted deputy, Ciro Di Marzio (Marco D’Amore). But it is his wife, Donna Imma (Maria Pia Calzone), who also takes on a leading role.