In this passage, Pyotr makes his purity test of the revolutionary faction more direct by asking each member a question that is meant to determine whether they may be an informer. The way that the group immediately turns on Shatov when he refuses to answer the question is an example of herd mentality, whereby people sacrifice their individual morality to appease a group. That immediate denunciation of Shatov also shows the risk of opposing the group, as it seems clear that Shatov is now considered a likely enemy, which could put a target on his back.