Like an overambitious young chef trying to concoct a reputation-making signature dish, writer-director Guillermo del Toro stuffs The Devil’s Backbone with too many disparate ingredients. Nearly all of the film’s contents are palatable, but they fail to meld into a satisfying creation.

Del Toro’s opening sequence is a grabber. Near the end of the Spanish Civil War, 10-year-old Carlos (Fernando Tielve), unaware that his father has been killed in combat, is taken to Santa Lucia, a boys’ school for orphans of the dwindling Republican forces. A formidable but dilapidated stone structure located on a vast plain, the school houses a skeleton staff that includes Casares (Federico Luppi), an idealistic, gray-bearded professor who doubles as the institution’s physician; headmistress Carmen (Marisa Paredes), the disenchanted, one-legged widow of a leftist poet; and Jacinto (Eduardo Noriega), a brutish caretaker filled with contempt for the school where he spent his childhood. Upon arrival, gentle Carlos seizes upon two disquieting anomalies—an unexploded bomb in the center of Santa Lucia’s courtyard and the ghost of former pupil Santi (Junio Valverde), who fleetingly appears at windows—and quickly attracts the enmity of bullying Jaime (Inigo Garces), Santa Lucia’s oldest student.

After briskly introducing their characters and setting, del Toro and his screenwriting collaborators, Antonio Trashorras and David Munoz, are poised to explore a plethora of narrative and thematic options. But they wrestle with more plots and ideas than their movie can comfortably contain. As a result, The Devil’s Backbone conflates too many genres to develop coherently: Gothic thriller, coming-of-age tale, political allegory, psychosexual quadrangle, and revenge melodrama.

Del Toro lurches from one subplot to another: Carlos struggles to stand up to his schoolmate nemesis. Casares’ decadeslong romantic longing for Carmen is frustrated by her purely physical dalliance with Jacinto, who, in turn, enjoys an ongoing liaison with Alma (Berta Ojea), a lissome young teacher. The school’s precarious survival is threatened by the Republic’s impending collapse. Santi’s ghost seeks retribution for his death. The tangle of plot threads allows little in the way of development of, or empathy with, the principal characters. When several of them meet with violent deaths in the film’s fiery climax, one feels oddly unmoved by their fates.

The multilayered story line is further burdened by the weight of obtrusive symbols, including several that pay homage to surrealist director Luis Bunuel: Carmen’s wooden leg (an allusion to Catherine Deneuve’s amputee in Tristana) and the slugs that fascinate Carlos (descendants of the slimy creatures that pop up in Diary of a Chambermaid). Add to these the courtyard bomb, the statue of Christ erected by the students, the lines of inspirational poetry that Casares obsessively quotes, and the rum-preserved deformed fetuses that adorn his study (to keep the school solvent, he sells bottles of the fluid, which is thought to cure impotence) and the viewer is faced with an excess of information to process.

Despite The Devil’s Backbone’s lack of focus, del Toro’s directorial skills are abundantly evident. He’s a master of atmosphere, snaking his camera through Santa Lucia’s shadowy, blue-black corridors and bathing his interiors in burnished amber light. His handling of actors is uniformly assured, whether dealing with experienced performers—the commanding Paredes has appeared in films directed by Pedro Almodóvar, Roberto Benigni, and Arturo Ripstein, and Luppi has worked with John Sayles and Jose García Hernández—or child actors. With the expert collaboration of cinematographer Guillermo Navarro (Spy Kids, Jackie Brown), del Toro has made a movie that consistently engages the eyes—even if it never quite connects dramatically or emotionally.

Moviegoers in search of a chilling ghost story are likely to be disappointed. Del Toro seems almost apologetic about his film’s supernatural elements, restricting Santi’s manifestations to several minutes. (Too bad, because his presentation of the boy’s specter—ghastly white, swarming with flies, and spouting a plume of blood—has major creep potential.) Santi’s restless poltergeist appears to be a metaphor for the filmmaker’s true concern—the massacre of Spanish democracy—but this connection is vitiated by the schoolboys’ rivalries and the adults’ sexual conflicts, as well as the wooden leg, pickled fetuses, and other bizarre distractions. And the rather cheesy climactic carnage feels tacked on to add exploitable elements to what would otherwise be a rather forbidding, hard-to-market mood piece. Those who yawned through last summer’s hit ghost movie, the overrated, soporific The Others, will find The Devil’s Backbone far more compelling, though they might regret del Toro’s failure to clarify his film’s purpose. CP