Not very long into Breakfast on Pluto, our blue-eyed, mop-haired hero(ine) boasts in a winsome, sing-song whisper, "Not many people can take the story of Patrick 'Kitten' Braden." Either I'm missing something or Kitten is spinning wild fantasies again, because his story is about as difficult to take as a spoonful of white sugar. Sure, it's a movie about a tranny sex worker whose father is a priest and whose foster mother is heartless and abusive. But the tone is all Mary Poppins.

This new collaboration between Neil Jordan and adapter Patrick McCabe (who also wrote the novel) lacks any trace of the macabre recklessness of their previous movie The Butcher Boy—not to mention the gleeful audience deceit that made Jordan's The Crying Game famous. The infant Kitten starts off small and pink. Bundled up in a quaint little basket and dropped off at the parish rectory, he's taken in by the aforementioned horrid foster mother, harassed at school, and soon turns the way so many pretty movie lads do—toward the forbidden makeup case. Through his (her?) quest to find his real mother, Kitten endures many Important Life Experiences—a total of 36, neatly labeled with "chapter" headings—but in the end, he's just as cherubic as ever, only with more defined cheekbones.

Cillian Murphy, as Kitten, is a statuesque beauty. With perfect eyebrows and porcelain skin, he looks like a hand-painted mannequin, more suited to some animated nightmare by the Brothers Quay than to walking and talking his way through a cheerful picaresque. Murphy isn't hard on the eyes, but he's unable to do anything real with the wisp of a character the filmmakers provide him. Kitten's impassioned frivolity is clearly supposed to be some sort of statement about the impossibility of facing the chaos of the world head-on. The film's creators have given the character the unfounded optimism of Candide and the foppish insouciance of Oscar Wilde—the makings of a world-class satirist. But Kitten's whisked past a parade of silly characters so quickly that he barely has an opportunity to engage them, much less mock their habits.

The pretext of looking for his mommy takes Kitten from the safety of an Irish village to the urban terrors of London. The pop music soundtrack, which assigns at least one glittery tune to each vignette, betrays the real purpose of his journey: an excuse for the filmmakers to drown us with '60s and '70s nostalgia. As a child the prepubescent darling plays war games with a cute mixed-race girl and a boy with Down syndrome who has a dangerous affection for robots. When he gets bigger, there's a druggy scene by a campfire which lamely justifies the film's title, as well as a hippie band that adopts him as a sideshow Indian princess, and a terrorist attack at a discotheque. Kitten's total detachment from every development—he emerges from the bombed discotheque fretting about the rips in his stockings—is meant to disrupt the imperative to treat history with respect, I guess. But instead it makes us as numb to what's going on as Kitten is.

The story is so ridiculously earnest, and the protagonist so consistently opposed to earnestness, that you might expect the filmmakers to do something with that tension, to upend your expectations at the end. (Remember The Crying Game?) Sadly, nothing like this comes. No matter how many times Kitten brushes aside tragedy with the refrain "Oh, serious, serious, serious," it's clear from the treacly plot that the filmmakers are set on the importance of being, well, you know.