Story related........To get this achievement, you need to visit 3 locations, Wells Park Middle School, Welty Storage, and Harless Mansion....
Wells Park Middle School
To enter the school, you need to go around the side and find the ladder on the ledge. Enter through the hole in the roof...just go down the linear path until you get to the statue. Interact with it and then you will need to rotate the cup till you get that small white light again. Exit out the window, and that's it!! Short and sweet....
Welty Storage
Enter the warehouse on the side by climbing the side of the tank and through the gate. Follow the linear path with a couple slight jump scares. After the fall you will hear someone talking, follow the voices, and take out the 4 unaware enemies. (Great place to knock out 4 of the throwing knives kills if you haven't already) Examine the body like you did with the ones at the bar. (His neck, chest and right wrist.) The two notes at the altar are not required. (Which is why they were outlined in yellow instead of blue in your Intel Vision.Exit the warehouse then up the ladder on the "tower", enter the hole then up the stairs. You will get a cutscene at the hole leading to the outside.From the hole, turn around and go outside. Then go to the right side with the "triangle" being careful not to fall down the hole on your left. Go through the hole, down the hall, then down the ladder. Its gonna be dark for a few seconds, to make this a LOT easier, I HIGHLY recommend calling Vito's squad to clear the goons out for you. Just before you make it outside, another batch of goons drive up, not a bad idea to use Vito's crew again.
Harless Mansion
As soon as you reach the driveway, 4 goons want to welcome you with open arms, ok I lied, their arms are full with guns.....aimed at you! Once you reach the mansion, go up the stairs keeping to the left side. Follow another linear path and drop down through the hole in the floor. Keep going for a kinda creepy cutscene. Examine the blue coat, war medal, and the pocket-watch outlined in blue if you used your Vision. The tape recorder is not required but its worth a listen. head out the open door, on the right is a note on wooden coffe table. From the note, go left and down the stairs. Be prepared for a surprise attack from 3 goons, first 2 with knives, 3rd with a gun. There is nothing on this floor, necessary, or otherwise, so follow the mission marker, and fall down the hole. In the Ceremonial Site, there is a tape recorder to listen to, a required book on the skeleton on the chair, and the required statue. go out he door, wait a few seconds..........and listen to the sweet sound of an achievement unlocked....