Home is Where You Left It

How black is the blackest treachery? Is the most callous traitor entitled to mercy? Steve pondered these questions. His decision? That at times the villain should possibly be spoken of as a hero.
Only the shells of deserted mud-brick houses greeted Steve Cantwell when he reached the village.
He poked around in them for a while. The desert heat was searing, parching, and the Sirian sun gleamed balefully off the blades of Steve's unicopter, which had brought him from Oasis City, almost five hundred miles away. He had remembered heat from his childhood here on Sirius' second planet with the Earth colony, but not heat like this. It was like a magnet drawing all the moisture out of his body.
He walked among the buildings, surprise and perhaps sadness etched on his gaunt, weather-beaten face. Childhood memories flooded back: the single well from which all the families drew their water, the mud-brick house, hardly different from the others and just four walls and a roof now, in which he'd lived with his aunt after his parents had been killed in a Kumaji raid, the community center where he'd spent his happiest time as a boy.
He went to the well and hoisted up a pailful of water. The winch creaked as he remembered. He ladled out the water, suddenly very thirsty, and brought the ladle to his lips.
He hurled the ladle away. The water was bitter. Not brackish.
Poisoned.
He spat with fury, then kneeled and stuffed his mouth with sand, almost gagging. After a while he spat out the sand too and opened his canteen and rinsed his mouth. His lips and mouth were paralyzed by contact with the poison. He walked quickly across the well-square to his aunt's house. Inside, it was dim but hardly cooler. Steve was sweating, the saline sweat making him blink. He scowled, not understanding. The table was set in his aunt's house. A coffeepot was on the stove and last night's partially-consumed dinner still on the table.
The well had been poisoned, the town had been deserted on the spur of the moment, and Steve had returned to his boyhood home from Earth—too late for anything.