The Indiana Jones and the Great Circle’s Order of Giants DLC has new puzzles from the very beginning, one of the more difficult being the Collegial Mystery in Casina Pio IV. Very few players actually take the time to solve the mystery, since most are following the main path, but it does bring some rich rewards if you take the time to add it to your journey. This guide will explain how to initiate the puzzle, where to find the clues, and finally, the solution for the safe combination.
How to Trigger the Mystery

Inside Casina Pio IV, you’ll find a large wall map, swing right and climb the staircase nearby. This path takes you through a small chamber and then into a larger one filled with religious artwork. Check the desk on the left-hand side of the room to pick up Federico’s Letter — that’s what sets the Collegial Mystery in motion.
Finding the Clues

The safe is sitting in the same room, but the code isn’t handed to you directly. To figure it out, look under the first chair in the row near the back — you’ll find Alessandro’s Letter. The note hints at numbers tied to specific paintings in both rooms. Here’s what each riddle refers to:
- The Apostles: Painting above the chairs → 12
- Beasts: Artwork on the right-hand wall near the Nativity → 2
- Cherubim: Nativity scene in the smaller room → 2
Cracking the Safe
Put the numbers together: 1222 and the safe opens. Inside, you’ll discover two documents along with a combat adventure book called Hard Crust.