- Having gotten, the Shiv, you can now easily get the Factory (Prison) key.
- From the Shiv, head back to the main yard and start over to the East to reach the wall.
- Head to the South toward the next item.
- Go to the crates just to the East, and use that to get past the locked gate and into the next area.
- Drop to the ground to the South, turning to the East.
- Sneak through the gate here and get the nearby Highwayman with a Takedown.
- Look to the East to find the key you need sitting on the table's edge.
- Once again, head back to the main yard to move forward.