Tweaked the timeline. https://baldursgate3theafflicted.blogspot.com/2021/08/home.html

Changed the parts about Eliette being the apprentice and about the missing children. Want to make it as accurate as possible. Thanks for bringing some things to my attention.

It is pretty clear, now, that Eliette likely escaped drow captivity and made her way into the Whispering Depths on the night Ilyn Toth was killed during the Dark Justiciar raid on 20 Nightal 1372. As the apprentice was making his/her way into the Whispering Depths to retrieve the key gem, Eliette ran into them and killed them. She didn't know what the key gem went to, so that explains why the Necromancy of Thay was still locked away in the Necromancer's Lair. Eliette just kept the gem for herself, thinking it was nothing more than a pretty gemstone. The only two people who knew about the book were dead.