I’m currently in the Gremory Laboratory, and I need the key to unlock the door. The instructions mention that I should search the room, and I’ve already retrieved the vial from the machine. However, I’m unsure what to do next, as I can’t seem to use it for anything.

Help please.

I'm having the same issue 

Read the note on the desk, it tells you where to find the key (under the doormat).