After you talk to Dr. Quentin about everything (and isn't THAT an uncomfortable conversation), go back to your apartment and look for a manila envelope on the doormat.
Hint 2
Inside are two pictures and 25 pages of letters. After you click on the envelope, the other items will appear separately in your inventory; right-click on them to examine them.
Hint 3
Read through all the letters; they're short and you don't have to memorize any of it, but you do need the background.
Buy me a coffee