This page offers a guide on where to locate and how to complete War of the Collectors, which is a Mystery located in Lunden, AC Valhalla. This mystery can only be accessed if you have built the Museum in your settlement and accepted the quest, A Rivalry for the Ages.
Speak to Maximilian
This mystery can be located south of Londinium Amphitheatre. As mentioned, before you can do this quest, you’ll need to build the museum and activate the quest from the museum owner. When you speak to Maximilian, and ask for his artifact. There are a few ways that you can approach this quest. IF you have Level 5 Charisma you can convince him to give you the artifact for free, but if not you’ll either have to pay 130 Silver for it or find another way to get it.
Stealing the Artifact
If you cannot convince him using your charisma, and you don’t want to give him that much money, you’ll need to figure out a way of distracting him so that you can grab the key on the stool behind him and steal the artifact from his home. If you want to steal the artifact, then you’ll need to find a distraction. If you walk down the road, you’ll find a small girl who you can hire to provide a distraction for a brief time. This will cost you 65 Silver but it is cheaper than paying Maximilian!
Wait for the girl to lead Maximilian away and then grab the key to unlock the building behind. You can then pick up the artifact on the table to the left of the entrance. The girl will give you a signal that Maximilian is returning and you can head out of the back door by breaking the lock.