Exploring the Lower City Sewers will eventually have you finding all sorts of things down in the smelly dwelling area and one of the things you find is a dead Kobold Thief.
If you check its inventory, you will find a map of the Lower City Sewers drawn on it with a spot marked, which is a hint that the creature was searching for a cache.
Around the dead Kobold Thief, you will notice that several spots can be dug up but not all of these will have a lot and instead something to insult whoever is looking for the cache.
All Marked Chest Locations
All the chests will be found around the dead Kobold Thief as it seems that whoever stashed their cache in the area had the intention of mocking whoever searched for the chests.
Each of the chests will be trapped and will require a Perception Check before they can be disarmed or else a Force Blast will be emitted.
Among the 5 chests (Dragon, Crown, Sword, Coin, and Gem), only one of them will have items in it while the others have letters meant to insult those who open them.
Opening The Right Chest
The only chest that will have items in it will be the Marked Chest: Dragon one and opening this will allow you to collect a certain amount of Gold along with Jewelry and a Gem.
In one attempt to open the chest, we obtained the following:
- 250 Gold
- Gold Necklace
- Jacinth
After reloading and attempting to open the chest again, the following was obtained:
- 268 Gold
- Gold Ring
- Pearl
This makes it safe to say that the loot from the chest is randomized, providing you mostly with over 200 Gold, a piece of Jewelry, and a random Gem.
Verdict
It is unsure who has hidden their stash in this area, and they might have known someone would be looking for it, which is probably the Kobold Thief.
Whether it was the Force Blast that killed the Kobold Thief or someone who caught them searching for the cache, it is unsure what caused its death.
Since the loot is randomized for each time you open the chest, you are bound to get different items, but this should often yield items worth at least 250 or more.