Galactic Bounty by William C. Dietz

evidently McCade's darts had wounded this one so badly it couldn't sustain an impersonation for more than a few moments.
    "We are the only perfect race . . . for in us the great Yareel saw fit to demonstrate the unity of all life." With that the alien began an eerie chant in his own tongue.
    A host of thoughts crowded each other, fighting for dominance in McCade's mind. A Treel. As he'd just seen, a Treel could impersonate any living thing which didn't exceed its own mass. But the Treel had to model its impersonations on something. The photos he'd found aboard the Leviathan. Photos the Treel had used to perfect his imitations. He remembered the photo of Laurie he'd found clutched in the dead man's hand. So the man had tried to identify his killer. But it hadn't been Laurie. She'd been aboard Pegasus with him. No, for some reason the Treel had chosen to look like Laurie when the tug's crew came aboard. Why? So they wouldn't recognize Votava from the fax sheets Naval Intelligence had sent out. It made sense. How long had the Treel posed as Votava, McCade wondered. Days? Months? Years? Yes, years probably. He remembered the discrepancy between the psych profiles before she left Mars, and after she entered the Academy. Somewhere between Mars and Terra the Treel had murdered the real Votava and taken her place. Then in the role of Votava, the Treel could have gone to work on Bridger. Feeding his anger and hate. And then when he'd learned the secret of the metal plate, urged him to use his new knowledge. Anger buried McCade's other emotions. A cold-blooded killer that could take on the appearance of anyone it chose. The perfect assassin. Suddenly another piece of the puzzle dropped into place.
    Turning to Laurie, McCade said, "Now we know how the bomb was placed on that autocart." And why I found your picture aboard the Leviathan, he thought to himself. "It was no sweat for the Treel to place the bomb while impersonating someone who belonged in the building, someone like you." Laurie looked puzzled for a moment, and then nodded her head in understanding.
    "That's right, Sam," the Treel said in a perfect imitation of Laurie's voice. "You aren't as stupid as you look."
    "Why?" Laurie said. "Why have you done these things?"
    The Treel made a hoarse coughing sound. A distorted likeness of Votava's face came and went. The Treel rasped, "My native planet lies just inside the Il Ronn Empire."
    "They threatened you?" Laurie asked. The Treel's protoplasm convulsed into a shaky likeness of a stern-looking Il Ronn before again collapsing into a shapeless mass. A dry racking cough issued forth and for a fleeting moment McCade felt sorry for the strange being.
    "Yes, primate, you speak truly," the Treel croaked. "While great of intelligence and beautiful to look upon, my race is few in number. Were it otherwise, we too would rule a great empire! But that is not the destiny Yareel granted us. We seldom mate, and then only on our native world. The Il Ronn have threatened to destroy our planet if we fail to serve them. The inevitable result would be the extinction of my race."
    "I'm sorry," Laurie said. "We oppose the Il Ronn. Perhaps we could help."
    "You're too late," came the hoarse reply. "Soon the man you call Bridger will lead the Il Ronn to the War World and then, invincible, they shall prevail throughout the galaxy."
    "Bridger . . . where is he?" Laurie asked urgently, cutting McCade off.
    She was answered by a hoarse sobbing which McCade supposed might be laughter. "It worked twice! We used the same trick twice!" The Treel chortled.
    "You mean he's here? Right here in the hotel?" McCade asked.
    The alien's laughter turned to hoarse coughing. "Yes . . . here. Like me he lies ill unto death. But soon they will come and take him. They will extract the information they require. Then woe unto man." Once again the eerie chant began.
    McCade opened his mouth to ask what the War World is, exactly, but never got the chance. Instead Laurie