No Turning Back — Mary Ann Steele

In this second volume of the two-volume sixth novel of the series, Marianne marries Sebastian, despite harboring troubling misgivings about doing so. Sebastian, now a teaching fellow at the University and a consultant to the Ministry of Internal Security, and Marianne, a full-time student, begin an arduous regimen of work and study. Marianne observes with dismay that Gavin, a swordsman capable of besting Sebastian in a duel, lusts after her.

Bianca accosts Sebastian, and pleads for his help, when she gets victimized by a blackmailer. When Sebastian and Basil lay a trap for the offender, he escapes after committing cold-blooded murder. Sebastian persuades Basil to use Marianne as a consultant. The ex-spy demonstrates how the murderer vanished. Threatened anew, Bianca again appeals to Sebastian, who duels and kills Dominic, a man who extorted credit from her. Gavin tells Marianne that Sebastian cold-bloodedly instigated a duel with a man he knew he could kill, and wanted dead. When Marianne confronts Sebastian, he masters anger, and explains that he cannot tell her the reason for the duel without breaking his word. The duelist and the pacifist talk out their philosophical differences, and achieve an understanding.

Confronted by a man who tries to use a faked disk he found in Dominic's effects to blackmail Sebastian, the outraged Security officer refuses Alan's demand. When Alan offers the disk to Marianne, she realizes that he must have tried to blackmail her husband. Sebastian finds to his relief that not only did his wife refrain from viewing the disk, she refuses to believe what the disk purports to prove. On hearing that the disk-maker might seek to blacken Sebastian's reputation among his colleagues at the University, Marianne suggests that they throw a party, invite both Bianca and key faculty-members, and quash the rumors.

When faced by a dire threat to the fragile accord between Gaea and Columbia, Basil persuades Sebastian to allow Marianne to infiltrate the headquarters of a radical group opposed to free trade, in hopes of quashing a plot to discredit Douglas, the Gaean Ambassador. When the murderer captures the infiltrator, she uses her skill at word-play to maneuver him into a situation where she can transmit a vital message to Sebastian. Bent on preventing the murder of the courageous Gaean volunteer, Basil and Sebastian mount a dangerous offensive. The marital relationship uniting the two former adversaries changes markedly at this juncture. This stirring narrative forms part of an ongoing saga of futuristic action, adventure and romance.