Summary
The party evacuates captives and Naa refugees, returns to Rosenthorne, and destroys Project Sunrise from both sides. Salmaya Nordithis's immediate counterattack kills Carrick Cinderforge and Trevor before Baby kills Salmaya; Gaby becomes Baron Brooverton and the returning refugees rebuild Drankov.
Detailed Narrative
The party spends the opening phase organizing the evacuation from Naa. Louisa now openly functions under her real identity and continues supporting the group. Rescued subjects from Rosenthorne's world are sent through first, followed by selected Naa allies/refugees and unusual biological cargo. Reginald operates the Naa-side machinery and prepares to overload/destroy it.
The group returns to the ruined Rosenthorne observatory after having been absent for several weeks in local-world terms. Carrick Cinderforge is waiting and is astonished/relieved that they survived. The estate lawn becomes an improvised reception/refugee area. There is immediate concern about how the Blazing Hood and local authorities will react to an influx of extraplanar people, but the rescue is now a fait accompli.
Reginald's Naa-side work and Carrick's local preparations allow the party to complete the original strategic objective. The bridge destabilizes and Project Sunrise is permanently destroyed, badly damaging the observatory/roof but separating the two prime planes again.
The party has barely completed this victory when Salmaya Nordithis arrives as the unresolved human-world antagonist. She attacks Rosenthorne riding/commanding a massive Sard, an intelligent magical siege-tree, and uses powerful defensive and offensive magic. Penwin, Carrick, Louisa, and the PCs join the defense.
The Sard's volleys kill Carrick Cinderforge, who is struck by enormous thorns while exposed near the manor. The party destroys the Sard and then closes on Salmaya. Salmaya uses extremely high-level magic and eventually casts Power Word Kill on Trevor. Trevor is below the spell's lethal threshold and dies outright; there is no ordinary rescue available.
The surviving party finishes the fight. Baby kills Salmaya after the others strip away her defenses. The attack is over, but Trevor's death permanently changes the succession.
In the epilogue, the family lawyer recognizes Gaby as the new Baron Brooverton. He becomes official guardian/protector of Medina and names her his heir if he has no acknowledged children. The GM describes Medina as Gaby's “half-sister-niece,” strongly implying Trevor was her biological father. Trevor receives a lavish cross-cultural funeral and a legal clause states that if he is ever revived he may reassume his title.
The refugees are integrated into the reconstruction of Drankov, which becomes prosperous and unusually diverse. Baby establishes a secret laboratory/research program with Reginald and imported Naa technology/biology. The family's prestige soars, but outside scrutiny increases.
The final political reveal is that Louisa is/was one of the GRE's top spies. Her loyalty to the organization is now divided by guilt over abandoning her sons and renewed devotion to them. She tries to shield the family, but the GRE turns its attention toward Westbridge and the Tatarmoff family.