If I may risk being pithy about the gravest subject in the wide world, we’re living through a golden age of documentaries about mass killings in southeast Asia. Joshua Oppenheimer’s extraordinary, extraordinarily crushing dyad of The Act of Killing and The Look of Silence, with their historiographical study of the murder of accused Communists in Indonesia in 1965, are already legendary among the sorts of people who would be inclined to seek such things out; coming right in between the two them, having made the festival rounds in the second half of 2013, we turn to Cambodia from 1975-’79, the period of the notorious and cruel Khmer Rouge, a regime under the leadership of dictator Pol Pot that attempted to turn the country Communist by the expedient of massacring Cambodian citizens by the tens of thousands and leaving tens of thousands more to die from the miserable conditions that took root in the country as a result of the Khmer Rouge’s mismanagement of everything that could possibly be mismanaged.

Among those who managed to endure this four-year hell was teenaged Rithy Panh, the sole survivor of his family. Many decades later, Panh devoted himself to constructing a documentary mixing political history with personal memoir, and thus we arrive at The Missing Picture, winner of the 2013 Un Certain Regard award at Cannes, nominee for the Best Foreign Language Film award at the Oscars, and all around, one of the most daunting and important works of non-fiction cinema of the 2010s. The film’s title refers to the blank patch left in the historical record by the regime: all of the images of suffering, death, and casual evil that Panh recalls from his experience living through it, but which were either destroyed by the Khmer Rouge or never physically captured on film, either as motion pictures or stills. The Missing Image sets itself to the goal of rebuilding those images and recording them, giving visual testimony to the terrible events perpetrated against Cambodia from within, reclaiming Panh’s memories and giving them a tangible form that the totalitarian Communist regime worked to prevent during its brief, brutal time in power.

It is, in fact, something of a reversal of The Act of Killing, which explored the nature of mass killings by providing the aging perpetrators of those killings with a forum to express their memories through cinema, and thereby condemn themselves through their own words. The Missing Image instead gives voice to a victim, and is much more straightforward in the way it recounts history and then indicts its villains, though this is the only way in which it is more straightforward than anything. In order to stage his memories, Panh didn’t film re-enactments; he instead opted to stage his personal history as a series of elaborate three-dimensional tableaux, populated by small clay figures sculpted by Sarith Mang, while the history of the Khmer Rouge and Panh’s experience of it is recounted by a narrator (Randal Douc in the original French version, Jean-Baptiste Phou in the English dub, which is how I saw it). As movies go, this one is full of a great many still life subjects, but Panh and cinematographer Prum Mésa use the camera to probe through the richly colored, oddly playful sets, bringing the staged events to life with surprising vigor, considering how we’re basically watching a bunch of posed dolls.

It’s not just pregnant, kinetic camerawork that blasts life into the sculptures, though; Mang’s deliberately crude designs have individual personalities and shifting emotions that should hardly be conceivable for modeling clay figurines produced in the quantities this film requires. The childish nature of the technique and aesthetic constantly and uncomfortably reinforce the reality that Panh was himself barely out of childhood when he lived through the events he relates. Between the primitivist style and outstandingly expressive poses and faces, the figures in the film load it up with emotional resonance that ends up walloping us hard, and repeatedly, giving added wait to what are already dreadfully powerful stories put across in blunt, declarative statements that neither sensationalise the events nor beg for our pity and sympathy.

When, as happens somewhat often, Panh incorporates actual footage sanctioned by the Khmer Rouge, the contrast between the badly-aged black and white film and the colorful, hand-made figures appearing to watch or even interact with the film footage pushes and already bold and unique film into some kind of new place altogether, with the director uniting his decades-old memories with the scraps of extant documentary material to produce impressive conflations of past and present, personal and institutional. Throughout its running time, The Missing Image is as much a study of the persistence of memories as it is a history of the Khmer Rouge, and it is in these moments that those two threads draw closest together, combining with exceptional emotional force and intellectual thorniness in a film that has plenty of both of those things to start with.

Like most films about mass death, The Missing Picture is relentlessly, even oppressively unpleasant. As it should be and has to be, really. But even more than such essential works of pure human misery like The Act of Killing, this argues strongly for its essential nature by basing itself around the idea that we must never forget events such as these and human capacity for doing ill. It is, explicitly, an attempt to catalogue and present memories before they have been forgotten, something like a one-man Cambodian version of Shoah. If we do not grapple with films like this, we risk losing the memories and record of the events they depict, and thus make it easier as a specifies to repeat such events: you don’t walk out of The Missing Picture having “liked” it, but even so, I can’t name a single film released in 2014 in the United States that I’d be more eager to encourage people so seek out and sit through and process it in all of its difficult, disturbing complexity. It is both great cinema and important journalism, a rare and privileged combination.