"Find space-fold inverter" is a mission objective in the side mission "Sub-Level 13" in Borderlands: The Pre-Sequel
Walkthrough
Head over to the East and into the first building on your path. This will give you your first Ghost encounter. Just inside you will need to deal with a Tork Queen inside the Sub-Level 13. Go to the hole and drop down into it. Follow the corridor as you can and head into the first door on the right. This time you will need to deal with a Ghost that you can't hurt with your normal guns.
Sub-Level 13 Mission Objectives
- Find Sub-Level 13 entrance
- Descend to Sub-Level 13
- Find space-fold inverter
- Disable junction box
- Search vents
- Listen to Harry's ECHO
Turn in: Harry's Remains