Lucas rewatched the video he had discovered several more times, pausing it here and there to focus on the behavior of the zombies during the attack. For the most part, it looked to be a little over one and a half minutes from a successfull attack to a full propogation of the infection into a new zombie. Regardless of what was causing it, the mechanism producing the reanimation could take hold rapidly. Yet another terrifying mystery to pile onto the list of inexplicable traits.
More puzzling to Lucas was what drew the attention of the zombies in the first place. Obviously, the zombies were focusing on something that drew them to uninfected humans, otherwise they would recognize each other as legitimate targets and attack each other. Also, they seemed to lose interest soon after the victims stopped moving, which would indicate that was an important factor. So at first he thought that it must have been something about the way people were moving or behaving.
However, upon one of his many reviewings Lucas noticed a motionless figure that had attempted to hide among the crashed vehicles in the street rather than flee through the mob riddled with confusion and panic. Despite not moving, he had been discovered and attacked by one of the infected. That made the idea that they were attracted by movement seem rather unlikely.
Although, it still might be possible the man did something the camera couldn't see, Lucas didn't think that was very likely anymore. But he had no idea what other possibility there could be. Either way, it indicated hiding by not moving would probably not work.
Examining the other detail remaining to his speculation, when the zombies abandoned their targets was also peculiar. They didn't move away as soon as the movement of their victim ceased. Instead, they lingered for many seconds afterwards. And when they entered their phase of shifting targets, they would choose to attack some people who were not moving, but being actively targeted by another zombie.
Once reselection occurred, they weren't at their new target for long, and when one of them abandoned a target, they all did. Each one of them responded as if they were responding to one, unknown cue. The evidence was right there in front of him, but what it meant was mystifying. As much as Lucas could figure, there could only be one of a couple of reasons for that.
Either they were somehow intelligent and communicating with one another, which seemed very unlikely considering the speed at which they behaved and the almost mindless way they dashed at their targets. Or they were capable of sensing somthing that led them to their targets and when the person was killed, they weren't seeing it anymore.
Lucas wondered. Were these zombies capable of seeing whether a human was alive or dead? Were they somehow capable of directly sensing human life?
Whatever mechanism could explain that ability was likewise confusing. Lucas had read accounts of living people who were thought to be dead, but who had only been asleep, breathing shallowly. Body heat might be an indicator of life, but the zombies were determining living or dead at a distance, they were abandoning the bodies before there was a chance for them to cool down.
With his mind filled with strange considerations and thoughts, Lucas began speculating how to test his idea. There had to be some way to tell if they were sensing human life and once that question was settled, the mechanism by which they did it could be examined.
