Study apartment 205
This is one of the side quests that you can complete in the Observer. You can open it after completing the initial part of the game, that is, after investigating the crime scene in apartment 007. This will unlock access to most of the apartment building.
For this task, you must go to the second floor and get to apartment 205 (use the maps on the walls that lead directly to it). There, you will notice a faulty door that makes some unpleasant sounds. Sit down and walk under it to get to the apartment (before you enter there, you can take the collectible painting lying next to the entrance to apartment 205).
Inside apartment 205, you will make many disturbing discoveries, leading to the conclusion that you are in an organ dealer's apartment. In addition to another collectible painting, there are many items to be scanned with EM or Bio-vision. Namely: two livers, heart, skin, biomass and computer (you can read all emails).
The most important takeaway is shown in the picture above: these are a couple of photographs. Examine the bottom left photo to reveal code 7441, which gives you access to the basement you want.
Explore the organ dealer's basement
Case 776 can only be continued if you gain full access to the basement during the main missions of the storyline (shortly after visiting the tattoo parlor and studying Elena's memories). Initially, the game allows you to explore the area at the entrance to the basement, while all the corridors and basements are closed by gates.
The basement you are looking for is numbered 028 - the entrance is shown in the picture above. Interact with the panel and enter the code 7441 you received.
In basement 028, you can find another collectible painting, but the most important find is the organ farm, which is shown in the picture above. Study it to learn about the available ways to complete this case.
The first option is to reboot the device to restore the organ production process. To do this, focus on the two computer screens showing the critical error message. Interact with the keyboards next to each monitor and press the green buttons to confirm the reboot.
Another option is to cut off the livelihoods of the farm and thus save it from suffering. To do this, interact with the lever shown in the picture and pull it out (alternatively, you can also remove the power cable connected to the organ farm).
Observer main plot walkthrough:
Observer side quests:
