I've gotten 6 out of 7 key conversations from Leah in Act 1. However, it looks like I missed one called "Tristam" from early on in Act 1. I read somewhere that you can just restart/redo the quest where the conversation becomes available in order to check it off as complete. When looking at the places where I can restart the quests I've already completed, which one is the right quest where "Tristam" becomes available? Is it Fallen Star (begin quest) or Fallen Star (Rumford at the Gate)? Or is it Legacy of Cain (begin quest) or Legacy of Cain (explore cellar)?
Is there a guide to all the "timings" of the key conversations?
I hope I explained my question clearly enough.