“‘And what makes you think it was us, that it was the good guys who wiped the servers?’ She half turned and smiled grimly. ‘Who says we are the good guys?’” 

Allison’s question to Holston presages the later revelation at the novel’s climax that it was the people of the silos themselves who caused the apocalyptic event that killed most of the world. It also highlights the conflict that many of the novel’s characters experience between upholding order in the silo and following their own moral compass—it is unclear which route would make them the “good guys.” This is the same conflict that eventually lead’s to Holston’s death. Allison’s doubts points to the mystery of who controls information in the silos, and to the importance of controlling that information. Her curiosity and search for knowledge are exactly the dangerous sort that Bernard tries to stamp out for the sake of the safety of the whole silo. 

“The enormous pent up pressure of the place was now hissing through the seams in whispers.” 

The sense of pressure bearing down on the people who live in the silo is a motif in Wool. The cleaning is a ritual that provides relief from this pressure, which arises from the unnatural condition of living in cramped, underground quarters. Holston thinks this as Allison, who is going to clean, is put in the holding cell. He feels how the tension in the silo is starting to lessen, as the cost of his wife’s life.