It was a raw and misty late afternoon in February during Mardi Gras. Spotlights illuminated the gloaming Marigny shadows with a surreal, almost funereal light. David Simon and Eric Overmyer huddled inside a doorway across the street from the Spotted Cat, watching Davis Rogan do a run-through of “Godzilla vs. M.L.K.” before Steve Zahn as Davis McAlary would sing it for the shoot. The music rattled across Frenchmen Street as crew members directed extras and music director Blake Leyh checked lev...