The achievement is unlocked during the Prince of Tossball main story mission. This is the mission where you investigate Bertie as a suspect.
- When you head to Piraeus Spaceport to interrogate "Black Hole" Bertie, make a save.
- Make sure you have a companion with you.
- Talk with Bertie until he says "I don’t wanna tell you. I’ll get in trouble."
- Pick the dialog option that invites your companion for the bad cop dynamic, something like:
- "What do you think, Parvati? Up for a little "good inspector, bad inspector"?
- Encourage the companion to continue as the bad inspector and make sure you do not pick a dialog option that has you interrupt the companion.
Credit to Auce for their
guide.