Action! Adventure! Airships! Starships!
The return to the Scout's Honor planet. Spoilers ahead for the trilogy. . . .
Starting with the observation that they are re-integrated with galactic society. It opens with three first-person scenes from new characters: one from a villain (of two) murdering the rest of the galactics on her base, to begin their real work; one of a girl whose boyfriend is shipping out on an airship; one of a new ensign in the Navy, on the escort mission for David Rice and Princess Callan.
And then David's point of view returns, as their two children -- Rob is five, and there's Anne as well -- wake them up before being packed off on a visit to their aunt and uncle so that David and Callan can inspect the progress of the bases, including the one in the opening scene.
Much derring-do results. It involves a challenge to single combat that they know will be refused; a cave; a political group with nasty tendencies; a weather-control device that crashes ships; a valiant distraction effort, and more.