Yep you got that right!
Call of Duty: Ghosts will introduce a completely new mode called "Extinction" and this mode is all about aliens.. what is this mode exactly about? still no solid information yet other than this leak: http://www.allgamesbeta.com/2013/10/call-of-duty-ghosts-extinction-mode.html
Call of Duty and aliens? oh yes please! the biggest FPS in gaming just got even better!