MAN, I'M STARTING to get all of these Lincoln-related properties confused. Just so you know, The Conspirator isn't the one where Matthew McConaughey dons a stovepipe hat and stakes vampires.

Rather, The Conspirator is basically JFK for the Civil War set, in which a politically minded director tackles the unsavory aftermath of a presidential assassination. Robert Redford—last seen debating foreign policy on both sides of the camera in Lions for Lambs—casts James McAvoy as a Union Army captain tasked with representing Mary Surratt (Robin Wright Penn) before a military tribunal. Mary ran the boarding house where John Wilkes Booth (Toby Kebbell) held secret meetings to plot Abraham Lincoln's murder. The powers that be, including Kevin Kline's ridiculous beard, want Mary to hang, so they bar her from civilian courts. The Constitution is being subverted to enact swift revenge and stabilize a nation through fear.

Sound familiar? Redford and writer James Solomon clearly see parallels to the Bush Doctrine and Guantanamo Bay, and approach their story with a particular melodramatic fervor. I guess since they can't directly point out the history of doom that's repeating, they try to make up for it with earnestness. The opening scene of McAvoy and a woefully miscast Justin Long bleeding out on the battlefield pretty much sets the serious tone; if the movie were slightly better, it'd be catnip for Oscar voters.

But it's actually probably better for the audience that it isn't. The Conspirator largely succeeds because it doesn't try harder: Redford never muddies his intriguing yarn with cinematic acrobatics. The movie is entertaining, if overlong. Perhaps its fatal flaw is that the mystery isn't much of a mystery at all—even if you don't know your history, it's pretty easy to see where it's all going.