Of all European nations, Denmark enjoys the nearest thing to a heroic record of resisting its Nazi occupiers—which adds both poignancy and punch to Ole Christian Madsen’s fact-based drama about two posthumously honored Danes. Framed without cynicism as a gangster picture (the point being that contract killing turns everyone into a thug, however noble the cause), this slickly produced picture stars the almost unbearably charismatic Thure Lindhardt and the saturnine Mads Mikkelson as co-assassins—one loves killing, the other makes a mess of everything but killing—charged with executing Denmark’s Nazi collaborators. Flame & Citron is less about the battle between good and evil than about losing one’s way in the fog of war, which makes it hard to tell friend from foe and harder yet to sort through the rules of engagement, and which complicates the heroic honor codes of movies about the “good war.” Jean-Pierre Melville’s 1969 masterpiece Army of Shadows exerts a palpable influence, but in its own right, Flame & Citron is the film that the horribly overrated Black Book could have been, had Paul Verhoeven not indulged in the puerile reversals of sensitive Nazis and treacherous partisans.