I keep picking up plot-relevant notes in side quests, only to have the game automatically dismiss them seconds later, before I can read the whole thing. I think the auto-dismiss trigger has something to do with guards, so I would try to kill all the guards in the area first, but it's not clear who or what will have a note, and loot transports and patrols can come at inconvenient times.
The notes don't show up in my key items or anywhere else I've been able to find after they get auto-dismissed. Is there any way to see these bits of plot I've missed?