Lirian placed the dead guard on the ground gently, and quickly picked up his torch, the torches acted as beacons in the night.
They weren't simply used to clear the fog, but they also acted as means for the guards on the walls to be able to ensure that they were moving and performing their rounds.
If the guards noticed that the torch wasn't moving they would send someone to check on the guard, at that point the dead guard would be discovered, and the guards would sound the warning bells.
The city had three bell towers, one was located near the western gate and one by the northern gate, and the bells could be rung if any trouble was spotted approaching the city, as for the third bell it was located on top of the highest tower of the keep.
