A taste of the novel (one of the more mysterious aliens on this Canterberian-Tales journey:
"A tank with treads, like a motorized coffin, stood in front of the window—a poor location for a creature whose fragile life-support system needed this kind of protection. The tank was decorated with engraved designs that Riley would have liked to examine more closely, but alien sensitivities were unpredictable. He had no desire to cause interspecies conflict, but the tank, for that’s what it most closely resembled, piqued his curiosity, if for no reason other than its unusual exterior. The tank had no windows, no obvious means of observing the outside world, as if the outside world was irrelevant or the occupant, if there was an occupant at all. It was impossible to discern anything at all about the interior of the tank. For all he knew, the tank itself might itself be the alien creature; or, if there was an alien within, it might already be dead or near-dead and being sustained by some high medical art."