full quote:

The prescience, he realized, was an illumination that incorporated the limits of what it revealed- at once a source of accuracy and meaningful error. A kind of Heisenberg indeterminacy intervened: the expenditure of energy that revealed what he saw, changed what he saw.

And what he saw was a time nexus within this cave, a boiling of possibilities focused here, wherein the most minute action - the wink of an eye, a careless word, a misplaced grain of sand - moved a gigantic lever across the known universe. He saw violence with the outcome subject to so many variables that his slightest movement created vast shiftings in the patterns.