Soul Barrier Stone
The soldiers in the city wall had gloomy looks on their faces because the beast horde was attacking the city gate, and the gate wouldn't last for too long. Moreover, there were too many beasts to deal with all of them in a short span of time.
As for the traps, for some reason, they found that there was one way which was completely clear of any traps and that all the beasts chose that way instead of just charging forward like everyone believed they would do.
They couldn't understand how could such a big area be without traps; even if a soldier made a mistake, at most some traps would fail, but in that path, it was obvious that there were no traps at all.
Furthermore, they couldn't believe that someone had really betrayed them because the beast horde was a huge danger for everyone, so even if there was truly a traitor among them, that traitor faced the same danger as them.