The most surveilled city on Earth can track a face in a crowd of two hundred, read a gait from a block away, and name a stranger before he reaches the corner. So how do you hunt an assassin the cameras cannot see?For NSA analyst Elena Carr, the pattern shouldn't exist: a single killer moving through three continents at once, buying phones in Singapore while walking the streets of Washington, slipping through every system built to catch him. Her superiors call it paranoia. Elena cal...