See “Cat’s in the Cradle”
Note: This is actually quite a frustrating mission if you don’t know how to do it correctly. If you fail to catch Morinth or you kill Samara instead of Morinth (requires sufficient alignment to have the option for this), Samara will not become loyal and you will not get the achievement.
The part that most people find challenging is actually getting Morinth to take you back to her apartment. To do this, you must select the correct dialogue options. Most of them are located on the bottom left of the dialogue wheel. Once you enter the VIP area, talk to the guy directly on your left. He will give you some info that you will use while talking with Morinth.
Correct Dialogue Options:
Art – Vaenia
Music – Expel 10
Drugs – Like Hallex?
Travel – I like danger.
Power – Power is its own reward.