ToME: the Tales of Maj'Eyal

I've been trying to unlock the necromancer on my current character, and was wondering a few things about the four pieces of lore I need. I assume it's all "How to be a Necromancer?" I have three of those currently. I've been hoping the last would show up for a while, but I've gone to the East and back and still no luck. Is there a chance it's in some place I've been, or is it just random and likely to still show up? Is there any places it won't show up? Also, do I need to read all four on a single character, or just find the last one on someone else and defeat the necromancer then?

Thanks for the help.

The best way to get it is to get to the Sher'Tul fortress early in a game and use the library to recover lore from other games, thus increasing the chance of the missing piece being found easily enough. Lore is pretty rare as a random drop, so the chance of getting all on one char is unfortunately slim.

Thank you, that solved the problem nicely. After a couple more characters at least.