Looks like even more furloughed workers are headed back to the office. This time it's the CIA, which plans to begin calling back thousands of employees today, reports the Washington Post. The agency's director, John Brennan, says the move is a response to "potential adverse cumulative and unseen impact on our national security." The exact number of returning workers will take days to determine, and officials say more could be called back in the future if the shutdown continues. Still, Brennan notes, only those "directly involved in our core missions" will return, and the continued absence of employees means "there are still important functions that we will not be able to perform." (More government shutdown stories.)