 Why does Loy Chuk build an artificial environment for Ned?
A scream of brakes, the splash into icy waters, a long descent into alkaline depths ... The icy breeze tore tiny puffs of dust from grotesque, angling drifts of soil, nearly waterless for eons. Loy Chuk had flown his geological expedition out from the far lowlands to the east, out from the city of Kar-Rah. A perfect preservative for organic tissue, aided probably during most of those passing eras by desert dryness. The final instrument he used to test the mummy, looked like a miniature stereoscope, with complicated details.
 He needs a habitat for Ned, so he can study Ned in a natural setting.
 He needs to keep Ned calm. If Ned believes himself to back in his own time, he will remain calm.  He realizes Ned is mentally unstable from the trauma of being brought back to life. He doesn't want Ned to commit suicide.  He needs a habitat for Ned until they can figure out time travel.  He needs a habitat for Ned, so he can study Ned in a natural setting.