Extremely simple. Once you're given the Most Wanted mission of getting back in contact with Lucius Fox titled "A Friend In Need," all you have to do is go to Wayne Tower on the map. From there, it's basically an interactive cutscene of walking into Bruce Wayne's office and interacting with the computer.
After a plot twist, you will have to quickly press the
button the moment a light blue pulse goes off around the villain's head. After that, the achievement will pop.