The heroes of Hogwarts are all grown up in the penultimate installment of the wizard series. A good thing, too, since Dumbledore’s dead, Voldemort’s on a terror spree and Harry, Ron and Hermione are on the run in the countryside. This is the first of the Potter movies not to use the school year as a narrative backdrop---Hogwarts hardly figures in at all---and it’s also the darkest yet, its shadowy cinematography representing a vibe that veers between violent and melancholy. Even the relationship stuff is downbeat, with a romantic triangle threatening to wedge apart the three superfriends. There’s some first-rate action, particularly in the early going, but the film suffers for being a preamble to next year’s finale. It’s a table-setter, not a self-contained movie.