Mary is left to stand trial before a military tribunal of nine Union generals, headed by one of Lincoln's pallbearers. Maryland senator General Reverdy Johnson (Tom Wilkinson) sums up the bleak situation: "No presumption of innocence, no burden of proof, no jury of peers, and no appeals." Compounding matters, her defense is provided by Frederick Aiken (James McAvoy), a Yankee war hero with little legal experience and a firm belief in her guilt. As Surratt says from her cell, "They've left nothing to chance."

Redford's film focuses on Aiken's slow realization that his client might be innocent, and his more horrifying realization that, unless the tribunal is placated with the swift arrest of her son, Mary's innocence may be irrelevant. As she senses the futility of her case, she becomes simultaneously more defiant—"I am a Southerner, and a Catholic, and a devoted mother, but I am no assassin," she avows—and more withdrawn, starving herself and gazing off in the distance, like the wife of a shipman gazing out at the sea. Aiken, meanwhile, becomes more impassioned in his defense, procuring an affidavit, deftly cross-examining witnesses, and slowly turning the seemingly intractable minds of the tribunal.

The prosecution—led by the wily Joseph Holt (Danny Huston), himself the marionette of War Secretary Edwin Stanton (Kevin Kline)—makes clear their desire for swift justice to preserve the Union. "I, too, hold sacred our rights," hisses Stanton to Aiken, "but they don't count at all if our nation ceases to exist." Aiken's counterargument can be distilled into his retort: "You're sacrificing our rights out of revenge. Too many of us have laid down our lives to preserve them." The echoes of Guantánamo are hard to miss, from this ideological clash, to the burlap sacks thrown over the defendants' heads, to Stanton's Rumsfeldian intimation that he'll settle for the conviction of either Surratt. Though James Solomon wrote the script 17 years ago, it's all very topical, made more so by Obama's recent announcement that Khalid Sheikh Mohammed and four others charged with conspiring in the 9/11 attacks will be tried before a military tribunal.

So heavily allegorical does this movie become, so entrenched is it in the ideas it stands behind, that at times it ceases to be a picture about real people. For 120 minutes I waited for any meager throwaway gesture from Aiken to show me what kind of man he is—think of the disbarred, down-at-the-heels Paul Newman downing a raw egg at the beginning of The Verdict—anything to show me his character is more than a pawn in the protracted history of American jurisprudence.

The absence of those personal details makes it hard to believe the characters really exist outside the trial. Whenever the film ventures from the confines of the courthouse or Surratt's prison cell—to the posh Century Club (from which Aiken has been blackballed for his defense of Surratt), to the parlors of friends, to the private lives of our protagonists—the acting stiffens into starchy reenactment. It would be better to limit the story to two sets, court and prison, and adapt it for the stage. A more troubling result of the film's myopia is the curious absence of any mention of slavery, as Ta-Nehisi Coates and A.O. Scott have mentioned, as well as the absence of any war-wrought destruction, on the glistening city or the minds of the characters.