Sherman’s Camp is Crawling

Head back to the infirmary to talk to Addy and start this mission. Next, ride to Sherman’s Camp. That location has Nests and a Horde as well. You can work on clearing the nests if you want while you have this mission active. The Liston Knife Addy needs is found inside the Gift Shop which will be marked in your Map.

To enter it, check the alley beside it to find the fire exit. Shoot the lock (with a suppressed gun to avoid alerting nearby freaks) then climb up using the ladder.

Once you’re inside, go downstairs and find the knife inside a glass display case. Interact with it to break the glass and get the knife. From there, just return to Lost Lake and return to the infirmary to hand the knife to Addy and complete the mission.

Video Walkthrough

Retrieving a medical knife in the infested zone of Sherman’s Camp