The woman at the end of last season who was giving Hersh his orders and seemed to be running the operation for relevant numbers. Back during season 1, Nathan said there were originally eight people who knew about the machine. I'm kinda interested to see how many of them get killed as the series continues. There was Finch, Ingrim, Alicia, Weeks (the guy who wanted to renegotiate the price and was then captured and killed by Root), Special Council (the guy who was killed at the end of last season), Control (presumably), and then two more who haven't been revealed. That's assuming of course that Control and Special Council have known about it from the start and aren't appointed officials.