Private Kahl is a quest to rescue an NPC of the same name (Private Kahl) who is trapped in the Foundry Core West. This quest is given to you by Captain Valenta in Minallah after completing Mad, Flaming Fyora.
After picking up the quest, make your way back to the Foundry Core West and head east along the south corridor. From there, head straight north until you reach the room where The Presence was controlling a Servant Mind (or, if you haven't progressed in The Presence (Quest) that far, a closed door) and make your way slightly west to a small hallway branching off of the main hallway just outside of the room. You will find Private Kahl at the end of this little alcove.
Once you told Kahl to make a break for the exit he will leave and take the wide hallway south to the east exit. You should have already cleared this hallway for him but it won't mean much - a group of 4 worms will spawn near the exit to impede your progress.
Kahl is amazingly weak. You will have to protect him as best you can, whether that means buffing and healing or trying to keep all of the rogues on you. Kill the four worms and watch as Private Kahl runs out toward the exit without so much as a thank you.
Sadly that's not the only problem you'll face. He'll run into a pack of three artila, meaning you will need to run after him with the worms on your tail. Don't let a single artila get a searer off on him or he will die.
Once both the worms and the artila are dead, return to Minallah to collect your reward.
If Kahl survives:
- Shielding Band
- Healing Pod
- Essence Pod
If Kahl dies:
Be wary of extra rogues if you didn't clear all of the rooms down the hallway Kahl runs down. Also, don't expect him to stick around and fight. He will sometimes just keep running. Be prepared to Daze rogues and chase after him.