Again a story-related achievement that cannot be missed.
*** Spoiler - click to reveal ***When you are on your way to locate Dr. Young you have to make your way back from Arkham North to Arkahm East. Be careful there are some snipers on the towers in both areas. Use to drag yourself up to the towers and take them out with a silent takedown by pressing. Once you are in Arkham East you will notice 2 snipers standing on the projecting roof of the mansion. Again take them out in what way you see fitting and use your claw to remove the grill in front of the vent shaft. Go through it to enter the locked down mansion and the achievement will unlock.
For more info, please refer to the video below.
(video credit: Chris Smoove)
Hope this helps you guys!
Any improvements? Please let me know in the comments below!