After you discover the phone booth in Forsaken Graveyard, thus completing the main-quest In The Shadow Of The Heretics, Hope will ask you to find four digits which form a password for the heretics.
The moment you answer the phone you will trigger the fourth main-quest in Luxerion, named Find The Code.
From the beginning you have to be aware that the code you will find is generated automatically, which means that is different than the one presented in the following walkthrough.
Nevertheless, knowing the locations of the four numbers required for the quest is important because you have to find them as fast as possible.
The following Lightning Returns: Final Fantasy XIII guide provides the necessary information on the locations where you will find the numbers needed for the main quest named Find The Code.
Description: “The mysterious rites that the Etro heretics attend each night appear to be connected to the murders of the young girls To get into the place where they are held, Lightning needs the pass code. After 6AM, four numbers will appear on walls across the city. Lightning must find them and then return to the Forsaken Graveyard in time for the next rites. ”
Requirements: Complete Main Quest 1-2: In the shadow of the heretics. Start the quest after 6 AM
According to the quest’s description, you will be able to find the numbers only after 6 AM, so make sure the clock shows the required hour.
Now, you will have to find all four numbers by visiting specific locations in Luxerion. For the first number you must head towards the Commercial District. Open your map, and notice the two green markers showing that the gates have been opened.
Under the lower marker is a dead end, similar to the letter L but reversed. Check the dead end and you will find the first number on the wall.
The second number is located SW from the first one, only several steps away. Enter the Avenue, and head left through the arcaded pass to reach the Back Alleys. Follow the stairs up, then turn right and follow the alley between the houses to see the glowing marker on the stairs at the end of the same passage. The third number needed for the code is easier to locate. All you have to do is to travel to the South Station.
Now, go to the Canvas of Prayers in the same area, and place Lightning with her back against the Canvas, facing the large Plaza. Turn left and you will see the marker on the wall in front of you; or if you face Chocolina, turn right.
Now, you will have to wait until midnight, or 12 AM, because the final number is in the area behind the Rusted Gate. The Rusted Gate is the one NW from Old Town, and it opens at 12 AM; therefore, when the clock hits 00:00 go through the gate to reach the Wall of Wealth.
To find the number faster, look for Lumina, because she is waiting for you. Next, watch the cutscene and return to the phone-booth in the Forsaken Graveyard.
Answer the phone and enter the code. Make sure that it matches the one displayed above. Watch another cutscene and get ready to enter a new area, named Sinner’s Corner, thus starting the next quest: 1-4 Rites For A Goddess.