I have a detective's notebook implemented now. As you gain clues, they will be added to your notebook, and you can flip through them to read them.
You can also carry them with you into the Mind Castle to help you remember exactly what you discovered while you make your deductions in the logic grid.
This is really shaping up to feel pretty great! I enjoy stalking around the mansion looking for suspects, possible murder weapons, and clues. Once I get this fleshed out with some actual clues that tie the various pieces together, it's going to be a fu logic puzzle wrapped up in a roguelike shell. I just hope I can get it all ready in time for the deadline!