After Willie's horse, Sable, goes missing, Willie suspects that he may have been stolen and he is forced to sneak into the coal mine, disguised at a pit boy miner, to look for his horse, and Ned even tags along to help. Meanwhile, Ben Frawley continues to adjust to life in the mine, while Spider continues searching for the hidden treasure, and Willie continues to resent Nellie and Ned's constant displays of affection in front of him.