The writer-director Zack Snyder has been sifting through his own past. There was, of course, his recent return to his once-scuttled vision for a Justice League movie, which resulted in a four-hour cut of the film released to great fanfare on HBO Max. Now heâs switched streamers, and delved further back into the timeline of his career to take up the zombie cause once more. Snyderâs first film was the scary-clever Dawn of the Dead, a remake of the George A. Romero film that put a mordant 2000s spin on Romeroâs gory satire of American consumerism. It was an auspicious debut, arch and stylish. Snyder got a bit lost in blockbuster bloat after that, but with his new film,