This achievement is a hidden fourth ending.
At any point before collecting Olivia Ambrose's Journal for Minnie Ambrose, kill Minnie at the Ambrose Manor. Return to your ship and you will be contacted by Spacer's Choice and Lucien Bancroft. He will ask you to collect the journal for him instead. Play out the rest of the story as you normally would. During the last mission Side with Lucien and turn on the Reactor. Lucien will then contact you again asking you to drop off the journal at Byzantium. Once you drop off the journal and talk to his contact, the achievement should pop.
You can reload a save to do this but make sure you have not collected the journal yet, the last step of the quest "The Red Tape of Command". If you have the journal Minnie will contact you and the normal endings will play out. Even if you kill Minnie and activate the reactor, the quest will auto complete and Minnie will respawn at the manor as if nothing happened. In anycase, Lucien will not contact you and the achievement unobtainable.