To unlock the hidden safe in Dr. Calvino’s workshop in the game Prey, follow this detailed guide for a step-by-step process:

Step 1: Locate Dr. Calvino’s Cabin
– Area: Head to the Crew Quarters section of the Talos I station.
– Cabin: You need to find Crew Cabin B specifically.
– Access: Use Dr. Calvino’s keycard to get inside the cabin. If you haven’t obtained the keycard yet, it can typically be found during the main storyline or by exploring nearby areas. One location you’ll find noteworthy is where the tumbler is placed on a hot plate, which is tied to a side objective and crucial for unlocking the “Coffee Break” trophy.

Step 2: Find the Safe Code
– Desk Note: Once inside Calvino’s cabin, search for a note on his desk. This note serves as a reminder regarding an anniversary.
– Safe Code: The note contains the safe code you need: 0523 (zero five two three).

Step 3: Locate the Hidden Safe
– Behind the Looking Glass: The hidden safe is located behind a Looking Glass in the cabin.
– Breaking the Glass: To reveal the safe, you’ll need to break the Looking Glass. You can use a wrench or any other suitable tool for this task.

Step 4: Unlock the Safe
– Entering the Code: After exposing the safe, enter the code 0523 to unlock it.
– Contents: When unlocked, you will discover various valuable items inside, including neuro mods and potentially other useful loot.

Step 5: Additional Tips – Using the Tumbler
– Custom Tumbler: If the safe isn’t fully accessible, consider placing Calvino’s custom tumbler on a scale within the workshop or station. Doing so may trigger the opening of a secret compartment that grants additional rewards related to the hidden stash.

Summary
By following these steps: finding Dr. Calvino’s keycard, reading the note for the safe code, breaking the Looking Glass to expose the safe, and entering the code 0523, you will successfully unlock the hidden safe in his workshop. This optional objective not only enriches the game’s exploration aspect but also rewards attentive players with valuable items—enhancing the overall gameplay experience in Prey.