Camouflage by Joe Haldeman

nitrogen.
    Nothing important had changed.
    "Let's go ahead and evacuate the room," Russ said, "and repeat the ten and twenty percent exposures. With no air in the room, any temperature increase in the artifact is going to be straight radiative transfer from the laser."
    "We ought to crank it up to fifty percent," Jack said.
    "If there's no change." Russ looked at Jan. "Okay?"
    She nodded. "How long to evacuate the room?"
    Greg Fulvia spoke up. "We figure about four hours to 0.1 millibar."
    "We ought to check the laser periodically as the pressure goes down," Moishe said from the screen. "It's designed to work in a vacuum, but that's after sitting in orbit for a long time."
    "What do you expect?" Russ asked.
    "I don't know. I expect machines to malfunction when you change their operating environment."
    "Do a system check every hour or so, then," Jack said. "The sensors, too, and microscopes. The positron's kind of a delicate puppy."
    Russ looked at his watch; it was almost noon. "Let's all be back here at 1700. Who do you need, Greg?"
    "It's all set up. I'll flick the switch and Tom and I can take turns looking at the nanometer." He talked to the screen. "You guys let us know when you're battened down." Moishe said to give them ten minutes.
    "Sails?" Russ said, a restaurant on the harbor. He and Jan rode bicycles over, and got drenched in a one-minute downpour. Jack was waiting for them at a balcony table.
    "Nice cab ride?" Jan asked, rubbing a bandana through her ruff of white hair.
    "Bumpy as hell." He pushed a bottle of red wine an inch in their direction. "I took the liberty."
    "A glass, anyhow." She poured for herself and Russ, and they sat down heavily, simultaneously. "Not a cloud in the sky."
    "Bicycling causes rain," Jack said. "Scientific fact."
    "Glad there's some science today," Russ said. The waiter came up and they all ordered without looking at the menu.
    "Every time we stress it without leaving a mark is a little science." She took a sip. "It's our technology versus theirs, or what theirs was a million years ago."
    "And where are they now?" Russ said. "Either dead and gone or on their way home."
    "Or they were us a million years ago," Jack said. "You read the Times thing yesterday?"
    "Lori Timms," Russ said without inflection. She was a popular science writer.
    "What was it?" Jan said.
    "Just a new angle on the time capsule theory," Russ said. "She thinks our ancestors deliberately renounced technology, and carefully wiped out every trace of their civilization. Except the artifact, which they left as a warning, in case their descendants, us, started on their path as well.
    "She handles the problem of the fossil record by postulating that they were as knowledgeable in life sciences as in the physical ones. They repopulated the world with appropriate creatures."
    Russ laughed. "And then what did they do with the fossil record that was already there? Carbon dating doesn't lie."
    "Maybe they cleaned 'em up. Had some way to find all the fossils and get rid of 'em."
    "That's a bit of a stretch."
    "Well, think about it," Jan said. "What if the 'million-year-old' part is wrong? What if that part of it was faked? Any technology that could build the artifact could bury it under an ancient coral reef. Then you only have to worry about archeology."
    "And the historical record," Russ said.
    " 'There were giants on the earth in those days,' " Jan said, smiling.
    "And fishburgers now," Jack said, as the waiter came through the door.

    -22-

    Bataan, Philippines, 5 April 1942

    The changeling waited until two groups of marchers had gone by, and there was no sound of nearby movement. It knew that the loose dirt of its grave would move around while it went through the hour of agony it took to change from one body to another.
    It planned to leave the head behind, and become a foot shorter. Japanese.
    "Agony" is really too human a word to describe what it went through. It was tearing its body apart and reassembling it from the