A half-dozen Gainesville firefighters lay pressed to the dirt, peering into a deep hole in an empty lot in the cold, dark night on Tuesday. They had been there for hours, digging and hunting with crestfallen volunteers behind them worried that their prizes would be lost and die — but at about 8 p.m., when temperatures were dipping below freezing, the last of five abandoned puppies came out of the hole in a firefighter’s gloved and muddy hand.