The snow-profile flight over the area showed a gap in the graphed line that flowed over the topographical map of the Sawtooths as the survey plane flew its daily scan. The hydrotech monitoring the graph reported the lapse to regional headquarters at Spokane and minutes later, a communications operator punched up the alternate transmitter for P11902-87. Nothing happened although the board showed the gauge's cobalt-60 beta and gamma still hot. Something had gone wrong with the tiny transducer transmitter. A man, or to be more precise, two men, had to replace the faulty device. The two men and the replacement gauge, trudged out again into the face of the rising storm. Troy and Alec pushed diagonally up the snow slope, pausing every few minutes to take new directional readings. The needles were now at right angles to them and reading well into the "hot" red division of the intensity meter. They still were ten feet below the crest and a cornice of snow hung out in a slight roof ahead of them. Both men had closed the face hatches of their insulated helmets and tiny circulators automatically went to work drawing off moisture and condensation from the treated plastic. "Wonder if that chunk is going to stay put while we go past," Alec called, eyeing the heavy overhang. Troy paused and the two carefully looked over the snow roof and the slope that fell away sharply to their right. "Looks like it avalanched once before," Troy commented. "Shall we operate, Dr. Patterson?" "Better extravagant with the taxpayers' money than sorry for ourselves," Alec replied, pulling the avalanche gun from his holster. It looked like an early-day Very pistol, with its big, straight-bore muzzle. "Let's get back a couple of feet." They kick-turned and skied back from the sides of the cornice. Alec raised the gun and aimed at the center of the deepest segment over the overhang. The gun discharged with a muffled "pop" and the concentrated ball of plastic explosive arced through the air, visible to the naked eye. It vanished into the snow roof and the men waited. Ten seconds later there was a geyser of flame and the smoke and snow as the charge detonated deep under the overhang. The wind whipped the cloud away and the roof still held, despite the gaping hole. "What do you think?" Troy asked. "One more for good measure," Alec said as he fired again, this time to the right of the first shot. The plastic detonated in another geyser of smoke and snow, but the small cloud was instantly lost as the entire overhang broke and fell the ten to twelve feet from the crest to the face of the slope and then boiled and rolled, gathering more snow and greater mass and impetus as it thundered down the slope and was lost in the storm. The dense clouds of loose powder snow raised by the avalanche whipped away in the clutches of the wind. "Well done, Dr. Patterson," Troy called as he leaned into his poles and moved out across the newly-crushed snow on the slope.