Fearless: The Ecology of Fear

A fraction of a second can decide everything.

Staff Sergeant Daniel Mercer has spent his career training for the narrow interval between recognizing a threat and acting on it. In combat, hesitation can be fatal. When a classified research program offers a biological modification designed to shorten that interval, the promise is simple: faster decisions, greater certainty, improved survival.

At first, the results look like success.

Reaction times drop. Operators move with unprecedented clarity ...