Standing in his office, the man who ran this classified facility, known only as Director Zero, watched the progress of the strange invaders on the security camera feed. He had an entire wall full of various monitors, each of them holding a different feed of the facility.
It was all closed circuit, absolutely no internet access or wayward signals that could be picked up in any way. Even their power came from within the facility, all their water was recycled and food was grown on site.
Their only connection to the outside world was a single telephone line, which was heavily encrypted. That telephone, of course, sat right on top of the directors desk. It was supposed to ring once a month, to give updates and reports from either party. It was also how they got new personnel or dealt with issues, such as food shortages from crop plagues.