There are two explicit narrative threads. One dealing with life in the hospitable placid galactic disk. The other within the perilous bulge. There is also a powerful subtext which seems ask “what is the point?”. What is the point of a life removed from the existential dangers we evolved alongside? When we can adopt arbitrary physical forms and psychological drives and perspectives? A solution proposed to avoid the morbid navel gazing, is for the bulk of a society to be individuals happy to exist in a sheep like state; time passing in a routine of work, gossip and sex. Only a small percentage need to entertain lofty thoughts or be capable of general intelligence. These individuals give society/species hope when faced with novel situations that endanger survival. Yet in times of peace and safety their life is lonely and futile – subversive stuff.
The two threads only meet in the sense that they are linked by the themes of safety and boredom.
We do find out who the Aloof are though.