Picture the old coot Clint Eastwood played in Gran Torino as Harry Brown, a retired Brit widower (Michael Caine) who’s mad as hell and not going to take it anymore. Caine is a marvel of an actor, a master of artful nuance. But in this movie he is at war with a script that reduces everything to its crudest elements. No sooner is Harry’s best mate, Leonard (David Bradley), a fellow veteran of the Royal Marines, killed by a gang of hoods than quiet, dignified Harry is making like Charles Bronson in Death Wish. The cops, led by Emily Mortimer and Charlie Creed-Miles, are no help. So Harry comes out firing. His victims are all set up as drug-dealing, gang-raping, unwashed scum. London rapper Ben Drew has a high old time playing the scummiest scum of them all. He’s hissable on sight. The better for us to snicker when Harry offs them. “You failed to maintain your weapon, son!” says this geriatric dirty Harry. In Gran Torino, Eastwood took on the moral issues that screenwriter Gary Young and first-time director Daniel Barber studiously avoid. It’s the difference between riveting and repellent.