Eight-hundred-year-old Douglas firs filled the next block from end to end. This one had been engineered to simulate the temperate rain forest of pre-Zero British Columbia, so its roof had been equipped with filters that damped the sun down to a steady silver glow that seemed to come from all directions. The lack of shadows made it seem brighter, in its way, than the unobstructed sunlight in the Chihuahuan biome. Ferns, moss, and epiphytes grew on fallen logs so thickly that they seemed to have been sprayed from a hose. A skein of faint paths ran through it. Kath Two followed one of them to the Kupol Grove: a relatively open space near the center, ringed by particularly enormous trees, where she found Doc, four of his students, his aide, and his robot sitting on moss-covered rocks and logs.