If you're a habitual fan of the underdog (in this case a role played by a horse), you won't want to miss Dark Horse, a documentary set in an economically depressed Welsh village. The story: Some of the village's residents pooled meager resources, and bought a race horse. The participating owners chipped in about $14 a week to pay for and train the horse, which they named Dream Alliance. Director Louise Osmond interviews the backers of the colt, as well as the woman who began the journey, Jan Vokes. Vokes worked as a bartender in the town, which had fallen on hard times since the closure of its coal mine in the 1980s. Dark Horse includes some re-enactments, a technique I mostly don't like, but the story is irresistible, largely because we can't help but root for Vokes and her neighbors to add some triumph to lives that badly need bolstering. Just as important, these folks aren't in it only for the money; they love the horse. Maybe that's why the whole genial lot of them were able to become working-class heroes in the sport of kings.