Judas and the Black Messiah is a mightily ambitious undertaking. Directed by Shaka King, the film has the dual focus implied by the title. Judas is Bill O’Neal (Lakeith Stanfield), a petty criminal who’s picked up by the authorities after he uses a phony FBI badge in a scheme to steal a car. Roy Mitchell (Jesse Plemons), equipped with a Bureau shield that’s legit and a mission to take down the Black Panther Party, recruits Bill, convincing him to insinuate himself into the Chicago chapter of the organization and serve as an informant. Bill not only makes his way in; he manages to develop a relationship with Fred Hampton (Daniel Kaluuya), the charismatic chairman in the local branch. Hampton is the Black messiah of the title.

King keeps the narrative firmly planted in the late nineteen-sixties, when the civil rights movement was arguably at its most heated, its most towering figures murdered into martyrdom and Black men across the country taking up arms, inspiring right-wingers to take a very different view of gun control that they would adopt before and after. The film crackles with the sense of fury and possibility that existed in the movement at the time. Kaluuya is particularly impressive at channeling that live-wire energy. He buries himself in Hampton, convincingly adopting his voice and cadence in delivering speeches of grand political power. The acting goes deeper than the pulpit performance, though, showing Hampton’s quiet cunning and reserves of caring. When Kaluuya is on screen, the movie longs to transform into a more traditional biopic, tracing the history that shaped the contours of Hampton’s being.

It’s not a traditional biopic, though, and O’Neal part of the story keeps intruding. Stanfield is fine in the role, but he’s too often denied the chance to take the character past the machinations he represented. He’s the linchpin of the plot, and linchpins need to stay solidly in place. That part of the story plays like The Departed drained of its brash pulp energy or a John le Carré thriller of veiled allegiances without the waft of intellectual dismay. There’s surprisingly little tension to it, either in the depiction of O’Neal’s mixed emotions or the menacing duplicitousness of the FBI. (On the latter point, it probably doesn’t help that Martin Sheen plops in a few times as J. Edgar Hoover, with gummy makeup and hammy overplaying that makes it seem like he’s angling to play the Penguin in some confused Batman reboot.) What’s positioned as the drama’s main conflict instead keeps getting in the way, obscuring the more compelling story of discarded and abused citizens demanding due rights and being viciously punished for it.

Judas and the Black Messiah tries to be too much, leaning hard on its hooky premise. Ambition is fine, but King would have been better off doing less. Hampton deserves to be centered in his story, not constantly elbowed aside. Judas betrays the movie, too.