67.
PELORAT automatically lifted his gloved hand to his face-plate and then took it away and looked at it.
"What is it?" he said, puzzled. Then, he looked at Trevize and went on, rather squeakily, "There's something peculiar about your face-plate, Golan."
Trevize looked about automatically for a mirror. There was none and he would need a light if there were. He muttered, "Come into the sunlight, will you?"
He half-led, half-pulled Pelorat into the shaft of sunlight from the nearest window. He could feel its warmth upon his back despite the insulating effect of the space suit.
He said, "Look toward the sun, Janov, and close your eyes."
It was at once clear what was wrong with the face-plate. There was moss growing luxuriantly where the glass of the face-plate met the metallized fabric of the suit itself. The face-plate was rimmed with green fuzziness and Trevize knew his own was, too.
He brushed a finger of his glove across the moss on Pelorat's face-plate. Some of it came off, the crushed green staining the glove. Even as he watched it glisten in the sunlight, however, it seemed to grow stiffer and drier. He tried again, and this time, the moss crackled off. It was turning brown. He brushed the edges of Pelorat's face-plate again, rubbing hard.
"Do mine, Janov," he said. Then, later, "Do I look clean? Good, so do you. Let's go. I don't think there's more to do here."
The sun was uncomfortably hot in the deserted airless city. The stone buildings gleamed brightly, almost achingly. Trevize squinted as he looked at them and, as far as possible, walked on the shady side of the thoroughfares. He stopped at a crack in one of the building fronts, one wide enough to stick his little finger into, gloved as it was. He did just that, looked at it, muttered, "Moss," and deliberately walked to the end of the shadow and held that finger out in the sunlight for a while.
He said, "Carbon dioxide is the bottleneck. Anywhere they can get carbon dioxide-decaying rock-anywhere-it will grow. We're a good source of carbon dioxide, you know, probably richer than anything else on this nearly dead planet, and I suppose traces of the gas leak out at the boundary of the face-plate."
"So the moss grows there."
"Yes."
It seemed a long walk back to the ship, much longer and, of course, hotter than the one they had taken at dawn. The ship was still in the shade when they got there, however; that much Trevize had calculated correctly, at least.
Pelorat said, "Look!"
Trevize saw. The boundaries of the mainlock were outlined in green moss.
"More leakage?" said Pelorat.
"Of course. Insignificant amounts, I'm sure, but this moss seems to be a better indicator of trace amounts of carbon dioxide than anything I ever heard of. Its spores must be everywhere and wherever a few molecules of carbon dioxide are to be found, they sprout." He adjusted his radio for ship's wavelength and said, "Bliss, can you hear me?"
Bliss's voice sounded in both sets of oars. "Yes. Are you ready to come in? Any luck?"
"We're just outside," said Trevize, "but don't open the lock. We'll open it from out here. Repeat, don't open the lock."
"Why not?"
"Bliss, just do as I ask, will you? We can have a long discussion afterward."
Trevize brought out his blaster and carefully lowered, its intensity to minimum, then gazed at it uncertainly. He had never used it at minimum. He looked about him. There was nothing suitably fragile to test it on.
In sheer desperation, he turned it on the rocky hillside in whose shadow the Far Star lay. The target didn't turn red-hot. Automatically, he felt the spot he had hit. Did 'it feel warm? He couldn't tell with any degree of certainty through the insulated fabric of his suit.
He hesitated again, then thought that the hull of the ship would be as resistant, within an order of magnitude at any rate, as the hillside. He turned the blaster on the rim of the lock and flicked the contact briefly, holding his breath.
Several centimeters of the moss-like growth browned at once. He waved his hand in the vicinity of the browning and even the mild breeze set up in the thin air in this way sufficed to set the light skeletal remnants that made up the brown material to scattering.
"Does it work?" said Pelorat anxiously.
"Yes, it does," said Trevize. "I turned the blaster into a mild heat ray."
He sprayed the heat all around the edge of the lock and the green vanished at the touch. All of it. He struck the mainlock to create a vibration that would knock off what remained and a brown dust fell to the ground-a dust so fine that it even lingered in the thin atmosphere, buoyed up by wisps of gas.
"I think we can open it now," said Trevize, and, using his wrist controls, he tapped out the emission of the radio-wave combination that activated the opening mechanism from inside. The lock gaped and had not opened more than halfway when Trevize said, "Don't dawdle, Janov, get inside. Don't wait for the steps. Climb in."
Trevize followed, sprayed the rim of the lock with his toned-down blaster. He sprayed the steps, too, once they had lowered. He then signaled the close** of the lock and kept on spraying till they were totally enclosed.
Trevize said, "We're in the lock, Bliss. We'll stay here a few minutes. Continue to do nothing!"
Bliss's voice said, "Give me a hint. Are you all right? How is Pel?"
Pel said, "I'm here, Bliss, and perfectly well. There's nothing to worry about."
"If you say so, Pel, but there'll have to be explanations later. I hope you know that."
"It's a promise," said Trevize, and activated the lock light.