In Animal Hospital , the key unlocks a safe in room 5. Inside the safe, players find lore items like a photo of Retina, a suitcase marked “top secret,” and a message saying the experiment was a success and that “the shadow knows everything.”

What it’s for

  • Unlocks the safe in room 5.
  • Reveals secret story/lore items.

What’s inside

  • A photo of Retina.
  • A top-secret suitcase.
  • A message about the experiment and “the shadow.”

In plain terms

The key is mainly a lore progression item , not just a random collectible. It opens a hidden story section tied to Ratthew and the game’s secret mystery.