The First Trans-Continental Expedition has found a hostile settlement on the far side of the North American continent and plans to do something about it:
"Giernas started to nod, then froze. A thought struck him, like the sun rising early over the low distant line of the Sierras to the east. Slowly, he began to grin."
-SM Stirling, On The Oceans Of Eternity (New York, 2000), Chapter Nine, p. 165.
Here ends the chapter. We notice that:
starting to perform a physical action, then freezing, are familiar signs of a moment of realization;
we recognize the sign before we are told that a thought struck Giernas;
we appreciate the colorful comparison of the thought's arrival with the rising sun;
we know that we will not be told what he thought until we see him putting it into effect;
he had nodded when told that the enemy would soon collect their tribute and that some local tribes would serve them in order to receive vaccination - this should give us some clues as to what Giernas thought, but it won't.
All will become clear when the author decides to tell us. Meanwhile, it is good to know that Giernas is confident of turning the tables on a formidable enemy. Stirling writes scarier villains than anyone else.