A Spike Lee movie called Blackklansman likely goes one of two ways, the question at hand being: are we getting a film by the director Do the Right Thing, Miracle at St. Anna, When the Levees Broke, and 4 Little Girls, or something from the man behind Chi-raq and Inside Man? Any one of those (maybe not St. Anna) would do, but the pleasures at hand in the first preview for his Cannes-premiering, I guess it turns out, comedy are plentiful, and make me glad for the latter. Judging by first reactions, it’s a sign of things to come.

The very strange true story of a black detective, Ron Stallworth (John David Washington), who managed to infiltrate the Kkk with careful deception, it’s (by the look of things) the sort of satire for which Lee’s prankster sensibilities might be especially well-attuned. Produced by Jordan Peele — who could...