WIKI / HOW THINGS WORK
Spying and dossiers
Gathering intel on other subjects, and what a dossier shows.
Spend nerve to spy on another subject. Your Spying and Intelligence decide how much you learn; a bad attempt can expose you.
What you learn becomes a dossier: an item only you can read, which goes stale after a while. Find yours under Inventory → Dossiers, grouped by who they're on, newest first.