Explorer (2002) is the sixth book in the Foreigner sequence and the concluding volume in the second trilogy. In this novel, the various factions go to Reunion station to confront the Pilots' Guild and possibly the alien ships.
In the previous volume, the Phoenix has been refueled at Alpha Station and prepared for the voyage, the atevi and Mospheiran passengers have come aboard, and the ship's crew has set course for Reunion. But all is not yet settled; the various factions are still not fully reconciled, the events at Reunion remain unexplained, and Jase, the new Second Captain, is still uneasy about his competence. The year long voyage isn't likely to be peaceful for Bren Cameron.
As Lord of the Province of Heaven, Bren is responsible for everything in the ship, but has only as much power over events as he can persuade others to give him. One of his tasks is to establish a working relationship with Sabin, the First Captain, and to encourage her to share more information with Jase. Just to add more complexity to his life, he also has to cope with Cajeiri, the ajii-apparent, who is practicing archery in the corridors and likewise being an active child. However, Bren does have allies in Jase, the ajii-dowager Ilisidi, the Mospheiran roboticist Ginny, and his atevi staff.
When they get to Reunion, they find that the station has been attacked, but not destroyed, and the Pilots' Guild is in firm, even rigid, control. They also find an alien ship observing the station. Bren takes measures to undermine the Guild and to contact the aliens.
Although this novel concludes a phase of the atevi-human story, there are many questions left unanswered, so another trilogy should be forthcoming. Right? Ah, the sweet agony of waiting for the next installment!
-Arthur W. Jordin