Henry, a retired racehorse, knows something is amiss when he takes his usual canter through the countryside, near the farm where he lives.
A mine, long closed, seems to be active again. Henry decides to investigate, and finds himself entangled in a ring of bad men, with very bad plans for a lot of local animals, including Henry's good friend, Shadow, the sheepdog. If he doesn't act quickly, he might be taken far away from his family and friends, and Shadow might meet an even worse fate!