Jia Zhangke's new film I Wish I Knew (2010) sits on the border of documentary and fiction: it is both his most objective (documentary-like) and his most subjectively personal (i.e., fictive) work yet. The Chinese director's previous films have gracefully alternated between documentary and fiction, often in explicit pairs In Public (2001) and Unknown Pleasures (2002); or Dong (2006) and Still Life (2006). More recently with 24 City (2008), Jia has combined fiction and documentary in the same film. The apparent modal dichotomy is bridged by ghosts: ghosts who haunt past, present, and future time, ghosts who connect the spaces documented in the film, and who lead us toward alternative ways of imagining history.

On the objective side: Jia frames, with his horizontally moving camera gliding ever so subtly by its subjects, a series of talking head interviews with a number of former and current residents of Shanghai. The interviewer, Lin Xudong, who has been Jia's longtime creative consultant and sometime film editor, is largely unheard. The subjects are caught in shots of varying scale. They tell stories of themselves or their parents, each of which catches a distinctive, now-lost aspect of Shanghai's cultural, economic, or political life. So we see gangster Du Yusheng's daughter Du Mei-ru talking about her father's famed bodyguards; master film director Fei Mu's daughter Barbara Fei and his actress Wei Wei talking about his filmmaking practice; Taiwanese directors Hou Hsiao-hsien, on late Qing-dynasty Shanghai eros via his film Flowers of Shanghai (1998), and Wang Tung, on his recreation, in the film Red Persimmon (1996) of his KMT-allied family's panicked escape from Shanghai as the Red Army approached to liberate the city. Post-Liberation, model worker Huang Baomei talks about meeting Chairman Mao and starring in a film about the incident; Zhu Qiansheng, who worked on Michelangelo Antonioni's documentary Chung Kuo—Cina (1972) discusses the Cultural Revolution's fierce campaign against that film. As we move toward the present, securities investor Yang Huidang tells about hauling suitcases of cash, and heartthrob blogger and race car driver Han Han brags self-mockingly about buying the most expensive car he could afford. How Shanghai aspirations have changed.

The people interviewed in I Wish I Knew, which screens this week at the Toronto International Film Festival (and next month at the Vancouver festival), are mostly famous, and predominantly from the arts world: this is a top-down historical chronicle, unlike the bottom-up small-town tales that made Jia's name 10 years ago. The film is organized around this cycle of interviews, embedded in some gorgeously shot, slow-moving portraits of Shanghai's contemporary cityscapes and worker residents (images more identifiably derived from Jia's previous palette). Many of the stories come from Shanghai's two brief "golden ages." The swinging cosmopolitan (and colonially controlled, gangster-ridden, Japanese-threatened) jazz age of the 1930s is the first. The second revival followed the Second World War during the civil war that culminated in the Communist Party victory in 1949 and the dispersal of many of the film's interviewees to Hong Kong and Taiwan.

The organization of the film suggests that, for Jia, place is at least as important a structuring principle as time. This spatial orientation is a long-running structural principle in Jia's cinema, from experiments with public/private space in the fiction/documentary pair Unknown Pleasures and In Public to the magical relocation of the world's most famous tourist spots to Shenzhen and Beijing amusement parks in The World (2004). In films like Platform (2000), Still Life (2006), and 24 City (2008), which critically reenact moments of epic historical change in China's recent history, Jia posits that reimagined space is where some kind of salvation lies: a reconstructed space is precisely where the traumas imposed by time can be captured, understood, and lived through. Time is tragedy; space is its consolation.

"I wish I knew where" seems to be Jia's key concern, even more than "I wish I knew when." His new film starts with a story from the Cultural Revolution in Shanghai in the late 1960s, then moves to Shanghai's first golden age for a series of interviews, before pushing back to the end of the Qing dynasty. Then we're back to the 1970s Cultural Revolution and the communist 1950s and 1960s. A return to the late 1940s leads through the '50s and '60s again, before we end with the 1990s and today. The chronological map of the film is not at all linear, but it does evince a clear preference for stories from the 1940s, from the end of the Japanese occupation to the "liberation" of Shanghai by the Chinese Communist Party.

But the film's spatial organization is more schematic. Jia starts in Shanghai with five interviews. He moves to Taiwan for five more, then returns to Shanghai for three interviews, to Hong Kong for three, and finally returns to Shanghai for the last two. Shanghai—Taiwan—Shanghai—Hong Kong—Shanghai. The Shanghai that Jia wishes he (and we) knew exists in these three places and has existed there for a long time. 1949 is the key (temporally fixed) crisis that shatters and disperses Shanghai, but Jia's film posits a Shanghai whose culture, vitality, and intellectual community continues to exist across the straits in Taiwan and across the colonial border (since 1997 mostly effaced) in Hong Kong. The tragedy of Shanghai's disruption and dispersal in 1949 finds its consolation in Shanghai's persistence in Taiwan and Hong Kong.

Jia's concentration on Taiwan is a refreshing way to look at Shanghai-after-Shanghai. The film offers a revisionist take on the usual thesis that Hong Kong has always represented Shanghai's double, its spiritual reincarnation. In Jia's telling, it is the KMT-allied officials, intellectuals, business elite, and their families, retainers, and followers who moved en masse (and in their eyes only "temporarily") to Taiwan, who serve as an essential repository of Shanghai culture and spirit. That puts this film in a slightly awkward position vis-à-vis Taiwan's later assertion of a distinct identity independent of China's, but it provocatively relocates an incarnated sense of Shanghai-ness to a flourishing independent (though somewhat chaotically managed) democracy rather than to Hong Kong, with its colonial, then mainland-dominated, political culture.

Why call the film Jia's most personal? I Wish I Knew incarnates Jia's deep cultural/political affinity with Shanghai, something intangible that lies at the core of this film. Perhaps Shanghai represents a moment in China's history that can't be recouped: when Chinese modern culture opened—both toward the West and with respect to its own historical heritage—to reveal its full potential. Recreating Shanghai-ness is, if not a way of recreating this moment of a tragically unfulfilled potential China of maximal cultural richness, then at least a way of celebrating an inflection point, a glimpse of what China might have been (or at least, what Chinese urban elite culture might have been) if not for the violent interventions of both the Guomindang and the Chinese Communist Party into the city's history. The film presents ample evidence to allow its viewers to deduce that blame for the extinguishing of Shanghai culture in Shanghai lies equally with both parties, an assertion that is hard to find in mainland Chinese mainstream texts and cinema. (I wonder how much of this implicitly provocative parallelism remains in the version cut for mainland release, which is apparently about 20 minutes shorter than the Cannes premiere version, and which one fervently hopes is not to the basis of the version, also shorn of 20 minutes, that is being offered by the film's international distributor MK2.)

It's not only political ideology that haunts the film. So do ghosts, both audible and visible. I Wish I Knew recreates lost memories through sound as well as image. This is Jia's most richly realized soundscape to date. Subtly insinuated (and sometimes prominently underlined) sounds from the real and imaginary pasts seep into the sound collage. Roars of the lion statues guarding colonial-era banks, gunshots from spectacular gangland assassinations, telegraphic beepings, airplanes roaring overhead bearing KMT soldiers away, 1940s Shanghai songbird Zhou Xuan's movie songs—all these stealthily inflect the interviews and contemporary cityscapes. Lim Giong's score performs analogous feats of sound montage magic, blending '30s and '40s tunes with a contemporary electronic palette.

The film is a remembrance of a lost past and an experimental imaginative projection, in sounds and images, of a lost future. Proustian in its fetishization of the eloquently world-restoring detail and its multi-layered construction of structures of memory, I Wish I Knew is no simple nostalgic lament (although such feelings are certainly embedded in its texture). There is equally a sense, quite close to Proust, that a lost past, when recovered, is continually productive of our present and possible futures. Indeed, the process of recovering memories—and, pointedly in this context, recovering "inappropriate" or overly "sensitive" historical memories that have been officially "forgotten" in the ruling ideology of the Chinese Communist Party—is a necessary condition for beginning to address and resolve China's contemporary political crises. Any intervention (such as I Wish I Knew itself) both offers a polemic about the present and stakes out the parameters of possible futures.

The ghost that underlies and animates Jia's film is incorporated in Zhao Tao, as a plot-free character wandering through Shanghai's spaces, gazing at the city's present but seeing its past (like the film itself). This figure of the wandering female spirit bears several meanings. She is, specifically, the ghost of the great Shanghai actress Shangguan Yunzhu's daughter Yao Yao, mourning her mother and brother, both of whom took their own lives; she is the audience's incarnation, or perhaps its guide, its Virgil, leading us like Dante through mysterious pathways; she is Jia himself, gazing at what no longer exists and weeping at the pain contained in the space between past potential and present imperfect. But finally she is the Shanghai that refuses completely to disappear, the spirit that even a World Expo Simulacrum Festival violently bolted onto the ruins of Shanghai's urban infrastructure can't obliterate: the sense of the cosmopolitan, with its daring, freedom, and danger, that animates and inspires the futures, even if they belong to other cities now.