This quest and achievement, which will occur during the second visit to Prague, has a few a priori requirements. First, you have to have gotten the neurocalibrator from Otar through a discussion (rather than stealing it), as necessary for
Second, part way through the quest to arrest Rucker in Golem City, you'll be contacted by Otar and asked to eliminate Louis Gallois. You can either warn him away or kill him, but you have to do so.
If you've done both of these, then after you return to Prague from Golem City, you'll be contacted by Otar with the start of the All in the Family quest. This requires you to first go talk to the owner of the strip club/brothel in the Red Light District. She'll give you the primary quest, which is to kidnap her son. He's in the apartments in the Dvali territory.
The best way to do this is to sneak into the area either using the sewer or by climbing into the apartment above the sewer (note that the storage locker near the sewer entrance in the red light district is the eventual place you're trying to bring the kidnapped person), head into the apartment complex, then stealthily work your way to the 3rd floor, knocking out guards when you can. Head into the middle apartment (the code for the door is in a nearby apartment if you can't hack it), then find the switch by the television to open the secret room. Here you can kill the security cameras. Go back and out quietly eliminate the rest of the guards.
Your target is in the laundry room on the ground floor. Once he's knocked out, carry him to the balcony in the apartment directly across and up one floor from the laundry area (i.e., the one you entered if you came in that way), out onto the balcony, and carefully drop him over the edge (save first, in case you accidentally kill him in the drop). Drag him into the waiting storage container and close it and the quest will end and the achievement will unlock.