Another story related achievement........
Follow Oscar on his "nickel tour", and you end, you will get a portable black light. After you examine the wall, you will get a short cutscene, and you will need to save Oscar. All you need to do is press
for stealth mode, and do a stealth kill......
You will be tasked to investigate the VIP area (which is a easy to navigate sewer system with your new black light) and the end, you will be in a circular area with 3 very small alcoves, in each alcove is an item you need to examine, a yearbook, a news article, and a picture (like the knife from earlier needs to be rotated until you see a small white "shining light")
After you examined the last of the 3 items, a cutscene with Bonnie will take place, after it is over, the achievement will pop.....