The Reavers didn't have to stop for food or sleep; they could go for days on end and never tire as they looked for their prey.
But humans had to stop for food and rest, or at least, that was what Rip had assumed. But they were going on three days, still following a scent on the wind.
The fighter was smart, well prepared, and probably a power user of some kind or other. There was no other explanation for what Rip was experiencing right now. The horde had flowed through City I, looking for the man, but no matter how hard they searched, he was nowhere to be found.
His scent was still as strong as when he had left the camp, but that was to be expected. The Reavers didn't need much to be able to follow it; a single drop of sweat was enough to keep them going in the right direction for days. So why couldn't they find him?