Navy Keeps A Secret in Plain Sight Shortly after dawn on a recent morning, two dump trucks and a water tanker pulled up to a new, unmarked complex of buildings at East Potomac Park, the grassy peninsula near the Jefferson Memorial. The drivers exited their cabs, knocked at a gatehouse with blacked-out windows and waited for a security guard to emerge from behind a locked door. A few minutes later, a panel of 10-foot-high security fence slid open, and the trucks disappeared inside, leaving the joggers and cyclists along the waterfront none the wiser about their mission. What goes on...