Set in 1909, a coal mine in Yorkshire, England has used pit ponies to haul coal for many years. When they are to be replaced by machinery that will speed up production and increase profits, three children – Dave (Andrew Harrison), Tommy (Benjie Bolgar) and Alice (Chloe Franks) – learn the ponies are to be slaughtered so they team up in a scheme to steal the horses and give them their freedom.