With Haruki Murakami, you never quite know. Unfolding their mysteries over vast spaces, the longer novels of this extraordinary Japanese author, especially The Wind-Up Bird Chronicle and 2005's Kafka on the Shore, seem to contain a lifetime's worth of Shinto dreams. In the shorter works, novels and stories alike, ambiguities tend to be confined to a single reverie, if not a single sleep.

Either way, the originality and strangeness are unwavering, and, for Murakami's many admirers, an exhilarating leap off the cliff of conventional narrative and methods of "knowing" a story's meaning. When a character in Kafka on the Shore insists she isn't a metaphor, another replies: "But metaphors help eliminate what separates you and me." Murakami's books are published in 36 languages.

After Dark is, in fact, a single dream of a single night. Taking place in nocturnal Tokyo, the story lasts a little under seven hours, a frame literalized using the visual aid of a clock, its hands changing, at the start of each chapter. The opening sentence, "Eyes mark the shape of the city," is written at 11:56 p.m. By 6:55 a.m., with the new morning light imminent, the action is complete. Better, it is suspended: "There will be time until the next darkness arrives."

That roving eye, an omniscient "pure point of view," follows a half dozen individuals around the city in the spirit, if not the tone, of Martin Scorsese's film After Hours. A young woman named Mari, leery of sleep, waits out the night in a Denny's restaurant. She is chatted up by a jazz musician called Takahashi, who knows her older sister. They talk, flirting modestly, and then he heads off to band practice.

Mari's solitude is interrupted again by a love-motelkeeper named Kaoru. A Chinese prostitute has been attacked in one of her rooms, and she needs a translator to find out what happened. Takahashi has told Kaoru that Mari speaks the language, and she agrees to help. Soon the teenager is learning grim details about some unhappy Tokyo lives.

The narrative eye, privileged but helpless, shifts between this group and two parallel, far more distressing, stories. One involves the movements of the assailant himself, a salaryman of unexceptional character, aside from his appetite for brutalizing women. Examining himself in the mirror, this man decides that, were he to concentrate long enough, "some other thing" might emerge from his own reflection.

There is also Mari's sister, Eri Asai, a literal "sleeping beauty" in her second month of slumber. Eri's condition, floating in her sleep state with a television screen quietly menacing her, constitutes the novel's biggest puzzle. Is she trapped in a profound depression? Is the salaryman her stalker?

When the TV actually swallows her – a popular conceit in Japanese culture, especially its horror movies – Eri is faced with annihilation. "The contact point in the circuit connecting the two worlds is being shaken violently," Murakami notes, "threatening to obliterate the clear outlines of her existence." This, despite that her younger sibling, now safely home after her long night of the Tokyo soul, has crawled into the bed with her, hoping to lure her back into the land of the wakeful.

"It's not as if our lives are divided simply into light and dark," Takahashi has already explained to Mari. "There's a shadowy middle ground." That middle ground is a familiar realm in the fiction of Murakami, and its nature, especially its casual refutation of binaries, including those of dream and reality, exceptional and ordinary, is elusive.

What looks like surrealism to the Western mind may read differently to someone immersed in certain Japanese traditions, and receptive to mysteries that require neither explanation nor resolution. Even the author's cipher assailant is given to meditations on how to "bring the advance of time to a halt" and "fuse his being with the scene behind him." Of course, previous Murakami philosophers have included Colonel Sanders and talking cats.

Minor works by major writers always have their creative reasons. While clunky in design and occasionally flat in execution, After Dark rides in the strong wake of Kafka on the Shore. Throughout his career, Murakami has shown a proclivity for building slowly, using short novels and story collections as blocks, toward longer works that further widen his already soaring vision.

The danger of these expansions lies less in their quirkiness than their inclination toward a position of such philosophical openness – a receptivity, in effect, to "never quite knowing" – that it nearly defies being captured in prose. Still, watching him gather his thoughts in preparation for another heroic rendering of his understanding of the instability of all things, including our selves as separate from other selves, is a thrill.