The Codex is read from the game's own files: every case, person, place, hero, skill and achievement, with nothing guessed. Case entries say who brings you each case and what its sheet asks, but never the answer; for that, open the case's walkthrough in Guides.
CasesAll 28 cases: who brings them to you and what the sheet asks. No answers.
PeopleThe 22 people of Dreskmark you can question.
PlacesThe seven places of Dreskmark.
HeroesThe eight detectives you can play and their starting skills.
SkillsThe six skills and every way to raise them.
AchievementsAll 100 achievements; the 42 the game keeps secret stay hidden.