Klaven's Tower

I've been staking out this tower for weeks, <name>. Recently a major shipment came through from Duskwood, and along with it came those guards. What are they? Your guess is as good as mine. I can tell you one thing - they aren't human. Anyhow, the shipment had a chest - which is what I assume those abominations are guarding. The zombie with the spikes holds a key we'll need. Get that key, get in the tower, and uncover whatever is in that chest. Take your findings back to Mathias.