Of course Mark wanted the N.I.C.E. to give him a job to do so that he could prove himself. It was Fairy Hardcastle who finally gave Mark what he was seeking. What he did not expect was to be put in charge of writing a propaganda piece whose purpose was to "rehabilitate" the murderer Alcasan. When Mark expresses disbelief that any educated person would belive such obvious rot, Hardcastle sets him straight. She tells Mark that the lower classes have too much common sense to be fooled by what they read in the newspapers. It is the educated classes who are far more gullible about what they read in their high brow publications. This rings true today when you see people with advanced college degrees following every fad that comes along while folks with high school diplomas are far more reluctant to belive what the media is trying to sell.
Fairy Hardcastle gives the example of Basic English as something promoted when it was invented by progressive Don. It was then shunned when a Tory (conservative) politician took it up. Basic English was a simplified form of the English laguage developed by Charles K. Ogden for those who used English as a second language. It has a vocabulary of only 850 words.
After Hardcastle is done with giving Mark a warning about what happens to those who leave the N.I.C.E. Mark fills the rest of his dreary day with a walk around the cemetery like gardens surrounding Belbury. It's quite the opposite of what Lewis likes about taking leasurely walks, lacking any connection with nature. The really disturbing part is when Mark hears the beastly cries of the animals the N.I.C.E. has caged on the premises. Rather than feel empathy for them, Mark fears being left out of the experiments, including vivisection, the N.I.C.E. plans to perform on these poor animals! After a while their howls are too much for even Mark to bear (no pun intended) so he goes back inside.