As a rule, the Holocaust is such a historically vital and delicate subject that it demands and deserves sensitive, intelligent onscreen treatment. In Darkness -- a complex docudrama about WWII refugee aider Leopold Socha (Robert Wieckiewicz) -- offers exactly that. It benefits from expert handling by veteran Polish director Agnieszka Holland (Angry Harvest) and an outstanding script by first-timer David F. Shamoon, who adapted the nonfiction tome by Robert Marshall. The result is one of the most emotionally overwhelming films of the year. The picture opens in Warsaw circa 1941, when sewer worker Socha agrees to conceal 12 Polish Jews in the city's subterranean aqueducts for the length of the Nazi extermination. In the beginning, his motives are more opportunistic than altruistic: In kind for his services, he demands hefty cash payments and collects personal artifacts, such as expensive watches, from the desperate fugitives. In time, however, Socha both softens to the exiles and forges a tighter emotional bond with them. Meanwhile, we get snapshots of the men, women, and children struggling to survive beneath the city streets. The characters include: a mother and father (Maria Schrader and Herbert Knaup) willing to do nearly anything to protect their little ones; a woman (Agnieszka Grochowska) heartbroken by the refusal of her confused sister (Maria Semotiuk) to accept life underground and her willing incarceration in a concentration camp; and an expectant twentysomething woman (Weronika Rosati) who conceals her pregnancy from the rest of the group and attempts to deal with prenatal complications made worse by the deplorable circumstances she must endure. In Darkness' core strengths are almost too numerous to mention, though three particularly stand out. Most significantly, Holland and screenwriter David F. Shamoon refuse to paint any of the main characters in shades of black or white: Among the evacuees, none of the individuals are flawless and none are evil. Socha is the most prominent example, with his heroic achievements yet calculated, self-serving motivations; others include a couple of Jewish men who pilfer money from their fellow escapees in the middle of the night and flee with it. It would have been far easier to present any of these men as saints, but far less credible. Also, the filmmakers understand where to draw the line with graphic depictions of Nazi barbarity. In its first ten minutes, the picture does deliver a lead-pipe blow to the viewer's sensibilities, with two devastating sequences of unthinkable cruelty. But those scenes pretty much mark the beginning and end of the movie's brutality: Afterward, they linger in the viewer's consciousness, so that we can constantly sense the palpable threat of violence during the long sequences when it is absent from the screen. Finally, Holland also deserves recognition for expert technical handling of the material -- two thirds of the drama transpires in dimly lit sewers, and while a less astute director could easily have turned out a murky mess with indistinguishable characters, here we never once lose track of the individuals' identities or their respective roles in the drama. Equally remarkable is Shamoon's script. He weaves together a multi-colored tapestry of contrasting lives and masterfully examines how extreme duress and uncertainty about the future shape the various personalities, especially as the characters impact and redefine one another. In this sense, In Darkness' closest cinematic antecedent is probably Hector Babenco's masterful prison epic Carandiru (which has the same episodic structure, also delves into the lives of social outcasts, and expresses the same infectious humanism). Incredibly, though this outing is only Shamoon's debut, his screenplay deserves to be mentioned in the same breath as Babenco's masterpiece, even if it lacks that picture's narrative scope. One wishes that In Darkness were much longer than its current length, which would give audiences the opportunity to delve more deeply into the lives of the endangered characters; this material would deliver an even greater impact as a miniseries. Even taking this into consideration, however, what is onscreen works beautifully and impeccably; the performances are uniformly superb, the narrative structure and character arcs perfectly judged, and the material itself tonally complex enough that the drama never once falls into the trap of oversimplification or pedanticism. Its success can be measured by its haunting resonance; long after the credits roll, one finds oneself reflecting on the beleaguered characters and hoping for positive outcomes in each of their lives following the end of the war. That is no small achievement.