July 1, 2025 8:44 PM (GMT+2) I tried using the code in Safe code, but it didn’t work. Probably because the memo is red and not handwritten, and as such it’s false. Or perhaps it’s just completely unrelated.

Note that the safe appears in Christmas picture with still some wrapping, so it was some kind of present.

July 8, 2025 1:23 AM (GMT+2) I checked the Christmas picture with the Magnifying Glass, but it gave no info whatsoever. On the other hand, I saw a miniature of the safe which seemed like perhaps it could reveal some info with the Magnifying Glass (but sadly I didn’t have it), see Safe miniature.

July 10, 2025 8:34 PM (GMT+2) After learning How to unlock safes, and considering the Christmas picture, I went ahead and tried inputting the Christmas day as a code following the MMDD format (1225), and it worked! Inside the safe, there was the 4th red letter and a gem. Mystery solved!