At the end of Christine Leunens’ grim 2008 novel, Caging Skies—just published in the United States in August—the narrator, a 20-something Austrian man named Johannes Betzler, addresses readers directly about the book they hold in their hands: “There are scenes I left out…for they seemed outside some core I was trying to hold on to. I simply wrote, and this is what came, and it had a life of its own, as imperfect and mutilated as our memories.” Now, this book has been made into an imperfect film, Jojo Rabbit—premiering on Friday, Oct. 18—which mutilates the source material for its own questionable ends.

In the book, teenage Johannes joins the local Hitler Youth as a true believer in the loathsome ideas of Adolf Hitler and the Third Reich—which makes him a nauseating narrator, to say the least. While in the Hitlerjugend, older boys regularly force him to perform sexual acts, and, at one point, he’s ordered to kill a bunch of ducklings with his bare hands, which he does. After he’s severely injured in an Allied bombing, losing part of his left arm, he spends much of his time at home; however, his loyalty to the Führer continues unabated. Then he discovers that his family is secretly hiding a young Jewish woman, Elsa Kor, in a space behind a wall. Rather than turn her in to authorities, he starts having secret conversations with her, and he gradually becomes sexually obsessed with her.

However, he never quite sees her as a human being. Even after his father and mother are killed, and his elderly grandmother dies, he makes no move to free her from her captivity. In fact, after the war ends, he tells her that Germany won, so that he can keep her all to himself. He does so, for years on end—in a section of the book that most vividly brings to mind John Fowles’ disturbing 1963 novel, The Collector, the first-person story of a man who kidnaps a woman and keeps her in his cellar. At least the ending is different.

In the last few paragraphs, Johannes tells of writing the text that becomes the novel itself—in which he doesn't show an ounce of self-awareness as he recounts his memories, or any guilt about his disgusting actions. It’s a deeply unpleasant read, as if The Diary of Anne Frank were told by one of the men who eventually killed her.

The film very, very loosely adapts the first half of the book—up until Johannes tells his fateful lie—but it changes so many details of the story that it’s nearly unrecognizable. It’s written and directed by New Zealand director Taika Waititi, who’s best known for the 2017 superhero adventure Thor: Ragnarok—one of the funniest and most entertaining films in the Marvel Cinematic Universe—and the hilarious 2014 vampire romp What We Do In the Shadows, which he co-directed with Flight of the Conchords’ Jemaine Clement. He’s a truly gifted comedy writer and director, but certainly not an obvious choice to adapt this particular material.

His adaptation is so different, in fact, that it’s hard to believe that he read more than the jacket copy. First off, the movie takes place in Germany, not Austria. Johannes (gamely played by newcomer Roman Griffin Davis) is a sweet 10-year-old boy who never really embraces Nazism and is never a danger to anyone or anything. His nickname in the Hitler Youth is “Jojo Rabbit” because he refused to kill a rabbit when commanded to do so. He’s so young and innocent that he even has an imaginary friend—Adolf Hitler himself (enthusiastically performed by Waititi), who largely acts as a friendly, encouraging replacement for Jojo’s absent dad; Jojo’s mother, Rosie, is around, unremarkably played by Scarlett Johansson.

The imaginary Hitler is new to the film, as are Jojo’s adult supervisors in the Hitler Youth: Capt. Klenzendorf (Sam Rockwell), an apathetic, one-eyed alcoholic; and the zealous and inept Fraulein Rahm (Rebel Wilson). They, like all the Nazis in the film, are broad caricatures—minor players in a Mel Brooks film, say, or an episode of the sitcom Hogan’s Heroes. Even when the Gestapo ransack Jojo’s house, it’s hard to believe that these clownish Germans pose a real threat to him, or to anyone—even after a major character dies. In fact, Rockwell’s character is later revealed to be a nice guy, in the end; the audience is apparently meant to forget that he is, in fact, a Nazi—and thus complicit in the Nazis’ atrocities.

Thomasin McKenzie, as Elsa—who’s also portrayed as younger in the film—gives a solid, nuanced performance, and the growing, genuine friendship between the girl and Jojo has a quiet pleasantness that brings to mind Waititi’s best work—the bittersweet coming-of-age tales Boy (2010) and Hunt for the Wilderpeople (2016), which deftly balanced low-key humor with family drama. The tone of Jojo Rabbit, though, is simply all over the place, with broad slapstick, the carnage of war, and feel-good moments all working at cross purposes. It all ends on a facile, unearned note: a dance to the strains of David Bowie’s “Helden,” the German-language version of “Heroes.”

Kirkus’ reviewer insightfully called Caging Skies “a dark, disturbing novel—but to what end?” Jojo Rabbit, by contrast, is a confused mishmash that wants to make audiences stand up and cheer, as the old saw goes. But to what end?

David Rapp is the senior Indie editor.