Not only was Zach keeping an eye on the Hunter family forces, but he was also putting up just enough resistance to lure them towards the center. The drones getting in the way of the Hunter family had been his handy work as well.
Only the mines had been in place from the start. Rest everything was under Zach's control as he slowly but surely guided them towards the mansion while creating the illusion that there were still people on the island.
Hitting the five-minute count down, Zach was sure that it was an impossibility for the invaders to escape being the target of the descending heavenly wrath. Therefore, he sent the activation signal to the drone he had put in place in advance.
