Where are Harry and Frodo when you really need them? Here is a magical-mystery movie with everything money can eagerly buy: big-name stars, boffo effects, a story pre-sold in a mass-cult fantasy novel. The only thing "The Golden Compass" lacks, alas, is magic. And its mystery is a little too mysterious. The picture looks great — director Chris Weitz and his town-size team of digital technicians have created a fantasy world of misty cities, gleaming dirigibles and intricate steampunk gadgetry that really pops. But in attempting to cram as much as possible of Philip Pullman's 400-page novel into a two-hour...