Video Guide!
To do this we need to have not completed the Animancy Method main quest yet. It is ok if we have already started it though. From the Wildwoods Outskirts Camp, we can head down to the river to find the waterfall cave. This is a secret area where the Steel Garrote are hiding out waiting to attack the city. So we will head down to the cave and confront them. When confronting them, make sure to choose options that are combative and eventually we will be able to attack. Then we want to clear the entire cave of enemies.
After that continue the main quest line through the quest Ancient Soil and when leaving the dungeon we visit as part of this quest, our companions will comment that something is burning, but that it doesn’t seem to be the city.