Conclusions

A Stone In Heaven is a sequel to the Captain Flandry series because it features Vice Admiral Flandry. Cairncross explicitly mentions the events of the concluding Captain Flandry novel,  A Knight Of Ghosts And Shadows. A Stone... is also a sequel to the concluding Polesotechnic League novel, Mirkheim, because Flandry reviews the history of Hermes since the events of that novel. A Stone... also references the first Young Flandry novel, Ensign Flandry, because Max Abrams' daughter, Miriam, now appears as an adult and informs us that her father has died. Although Flandry did not get either of the women that he really wanted, he settles down with Miriam and they walk away into the autumn - very much a conclusion. Flandry will appear in one more novel but it will focus on his daughter, not on him. And then history will continue beyond the lies of any individuals. The series culminates millennia later.