Dugan resumed his climbing. He was lucky.
About forty feet above the tunnel entrance, he came to a small latticed hut. It was locked with a formidable padlock.
Dugan twisted the flashlight head to its smallest aperture and with the resulting needle beam he looked over the little building. Though small and in the complete shadow of the trees, it was thoroughly camouflaged — brown with olive-drab splotches all over it. The whole roof was hinged, with the padlock on the downward side of the slope. The padlock was supplemented by a wire to which a soft lead seal had been attached. Dugan shrugged and said to himself,
"Okay, okay, if they want to make it hard on that side…"
He tapped the pins out of the hinges on the far side, using the steel rod from his portable telescope for the purpose. It ruined the instrument, but that was a small price. The blows, delivered by the German monkey wrench with his handkerchief wrapped around it, did not make too much noise. The pins came fairly easily. Dugan lifted the roof of the little building.
It was the size of a very small dog-house.
Inside there was the one big valve — something like an oversize faucet. At its base there was a steel arrow and three small wooden plates. Dugan flashed his needle beam on them. The left one said: RIVER OVERFLOW. The middle one said, quite simply: BOTH. The right-hand one said: SEPTIC TANKS ONLY. The needle now pointed straight at RIVER OVERFLOW.
Dugan wondered for a moment. Would it be better to put all the radioactive sewage into the tanks, thus flooding Atomsk with its own waste? Or should he shift the valve over to BOTH, so that the Russians would not discover their predicament until the next routine inspection of the valve?
He had an even better idea.
Using his steel rod, he shifted the big ring-topped valve until the needle pointed to BOTH. Then, holding the ring-handle straight in line with BOTH, he beat the indicator out of line until it pointed back to its original position on RIVER OVERFLOW. He rubbed his hand in the dust, spit in his palm, and used the film of thin mud to smudge over the evidence of the valve's having been touched.