When Caleb Carr’s The Alienist was published in 1994, it was an offbeat genre mashup. It was a serial-killer procedural—a category at the height of its popularity thanks to Thomas Harris’ smash bestseller The Silence of the Lambs. It was also a historical drama set around the turn of the 20th century in New York City, featuring numerous cameos of historical figures, à la E.L. Doctorow’s Ragtime.

Film rights to The Alienist were quickly snatched up, but despite the story’s novelty, an adaptation didn’t materialize until 2018, when the TNT network aired the first season of its TV series of the same name. A second season, which premieres on July 19, adapts Carr’s 1997 follow-up, The Angel of Darkness. Unfortunately, it only highlights the flaws of its source material.

In The Alienist, set in 1896, New York City police commissioner Theodore Roosevelt enlists the help of noted psychologist Laszlo Kriezler (called an “alienist” in the jargon of the era) and newspaper journalist John Schuyler Moore in investigating a series of horrific child killings. They, in turn, are assisted by others, including New York City Police Department secretary Sara Moore, and successfully solve the case. Kirkus’ reviewer wrote that the novel was “gripping yet lifeless, as evocative period detail jostles with a cast of characters who are, for the most part, as pallid as the murder victims.” They aren’t wrong; the setting is far more interesting than the characters, or even the murder plot. A similar problem carries over to the sequel—and its TV adaptation.

The Angel of Darkness also focuses on grim child murders (this time, babies), but it adds an element of international intrigue when the daughter of the Spanish diplomat is abducted in Manhattan. Kreizler, Moore, and Howard (who’s now a professional PI) duly track down the suspect with a combination of shoe-leather sleuthing and, in the alienist’s case, supernaturally accurate psychological profiling. The mystery takes them to a wide array of locales, from the gangland area of downtown Manhattan to upstate New York. The colorful Roosevelt is only briefly in this installment, set in 1897—he was assistant secretary of the Navy at this point—but there are guest spots by other famous types, including Clarence Darrow, who serves as the attorney for the murder suspect in an extended trial.

This trial—and Darrow, for that matter—don’t appear in the eight-episode TV adaptation, which pares down the source material considerably. For instance, the book is narrated by a minor character—Kreizler’s assistant, Stevie “the Stevepipe” Taggert, who recalls the story in 1919—but in the show, Taggert barely appears, and several other players are simply deleted. Few historical figures make their way into the show, although newspaper publisher William Randolph Hearst appears as the godfather of Moore’s fiancée. Hearst isn’t in the novel, though, and Moore isn’t engaged to be married; neither is he engaged in a secret love affair with Howard, as he is on the show. At another point in the book, the investigators go to Saratoga—but not in the adaptation, where such a move would likely have been too expensive.

The changes go on and on. Despite it all, the show does manage to get across a decent thumbnail sketch of the original plot, and the costumes and sets are often breathtaking in their attention to detail. But as Kirkus’ reviewer noted of The Alienist, the main characters mostly feel wooden and lifeless—aside from the main villain, who, by contrast, chews the well-designed scenery.

Luke Evans as Moore and Dakota Fanning as Howard are fine actors, and they do their best here, but they’re done no favors by stilted dialogue (“Who would have thought a newspaperman’s occupation would be this hazardous?”) or the aforementioned, ill-advised romance subplot. Inglourious Basterds’ Daniel Brühl is quite convincing as the genius Kreizler, but he, too, is saddled with a clunky relationship storyline when the alienist meets a psychologist colleague, Karen Stratton (Lara Pulver), invented for the series. It seems as if the show’s writers were convinced that love would conquer all, or at least make the characters seem less one-dimensional—but as Stevie says in the novel, on another topic: “That…was what alienists meant when they talked about ‘delusions.’ ”

David Rapp is the senior Indie editor.