Empery - Trigon Disunity, Bk 3 Author:Michael P. Kube-McDowell Merritt Thackery is still touring around in space and time relative to those back on earth, trying to make people aware of the threats that exist, even by appearing to those who are far in his future.
All this travelling eventually leads him to discover something about the enemy, the Mizari, that is not quite what is expected.