[ Register or Signin to view external links. ]

This achievement is missable and is earned for completing Side Mission 09, All in the Family.

There are a few prerequisites that must be met before this side mission can be started during your second visit to Prague (after returning from Golem City). Please see below for what must be done throughout your playthrough:

Complete Side Mission 04.
End the conversation with Otar peacefully and promise him that you will return a favor down the road.
During Mission 7, The Rucker Extraction, Otar will give you a call and ask you deal with Gallois.
Complete this secondary objective ASAP. If you miss it, Side Mission 09 will be unavailable when you return to Prague.
By completing the prerequisites above, Otar will call you once you return to Prague. A Point of Interest will then appear on your map, so just follow the objective waypoint to The Red Queen and meet Masa Kadlek. Speak with her and agree to help her out; this will start Side Mission 09. Please keep in mind that if you are spotted during this mission, it will automatically fail. The achievement will unlock once the mission has been completed.