 Matt and Festus bring a particularly notorious killer into a town on the edge of a desert, where the sheriff cheerfully informs the killer that "tomorrow we start working on the gallows." The sheriff spoke too soon: the killer gets the drop on him, murders him and flees into the desert. Festus, who stayed behind to borrow a new mule, goes in pursuit but is bushwhacked in his own right. Festus, however, is rescued by Ben Snow, a hermit who was a gold miner many years earlier -- only to be shot in the leg and left for dead by his partner. Snow is half-crazed ("I d even make friends with a snake!") -- but he actually found his gold mine, a spring which provides him with water and shelter and food from desert animals. He s panned the spring incessantly and racked up a huge cache of gold dust. Snow might be able to get out of the desert (he s tried before and left water caches as far as he could walk), but he s so bent out of shape that he refuses to go without the gold -- many dozen pounds of it. So he steals Festus s weapons and handcuffs, turns them against them and makes Festus into his "pack mule." When Festus asks why, Snow explains that he will buy up the town where his ex-partner fled and make life a living hell for the man. He also warns Festus that if he collapses, "I ll shoot you like a mule gone lame!" With all the cards stacked against him, Festus sets out carrying the huge sacks of gold, while Snow follows in his tracks under the blazing sun.