BlacKkKlansman

There are some stories that are so absurd that they have to be true, like the black cop who joined the Ku Klux Klan. In 1979, Ron Stallworth of the Colorado Springs Police Department called the KKK and asked if he could join, and they said yes. Of course, infiltrating a violent racist group is a bit tough when you're African-American, so the CSPD recruited a white officer to attend meetings in person, and pretend to be white Ron Stallworth, while the real Ron Stallworth became the voice at the end of the phone.

Spike Lee co-writing and directing a story where the cops are the good guys may seem like a change in direction for one of America's most political filmmakers, but this is pure Lee, at times both scathingly satirical and trenchantly earnest. As the real Ron, Ballers star and former football player Washington catches all the facets of being a black undercover cop in the Seventies – while he's pretending to be white Ron, he's also running surveillance on the campus black consciousness groups, and in a relationship with one of that group's leading lights, Patrice Dumas (Harrier). Not that this is some one-dimensional tale of Stallworth's political awakening: Instead, he is the voice for redirecting the power of the police against the real threat, and his friendship with "white Ron," aka Flip Zimmerman (Driver at his twitchy best), never lets go of the fact that it's the Jewish detective whose life is really on the line in every one of those Klan meetings.

But for all its amazing high points (and this satirically minded takedown of the ludicrousness of the American racist right has many of those) BlacKkKlansman also shows Lee at his weakest. The slight running time drags, a sensation not helped by Terence Blanchard's underwhelming score. That's a tragedy, considering how much he helped build the tempo of Lee's last narrative feature, 2015's equally scattershot but much more successful Chi-Raq.

And it's not a question of Lee dropping the narrative in favor of moments of polemic – in fact, Harry Belafonte's recitation of the testimony of a lynching survivor is one of the most powerful moments. Rather, it's when he falls into his adoration of classic Hollywood stylings – such as an earlier, equally polemical scene with Corey Hawkins as Kwame Ture, surrounded by floating heads – the BlackKkKlansman seems rudderless (the heavy-handed use of an oddly overdubbed clip from Gone With the Wind is similarly baffling, especially when followed by a hysterical sequence with Baldwin as an old-school, buzz-cut racist trying to record a recruitment film).

As a director of actors, Lee is still one of the best in the business, as proven in scenes like the locker room banter between Stallworth, Zimmerman, and Buscemi in a cameo role as Flip's old partner Jimmy – sequences that reinforce the real Ron's belief that, yes, the system can be changed from within. Similarly, the real Ron's interactions with the real David Duke (Grace playing the Grand Wizard as a chest-puffing middle manager) are glorious comedy with an edge. Yet there's a sneaking suspicion that Stallworth's life deserves a better retelling (doubly frustrating, since Lee's track record this century as a documentarian is much more reliable than his narrative work). Much like late-era Steven Spielberg, Lee has become a master director who has forgotten how to tell a story.