Ascendancy of the Last — Lisa Smedman

Is it the end for the Lady Penitent? Is it the end for Lolth?

Lolth has come out of hibernation with a plan that may seem too ambitious even for her, and to pull it off she'll need the help of a drow who's betrayed her at least once already--a drow she's transformed into the demonic Lady Penitent. The shocking conclusion to a trilogy that will change the Forgotten Realms world forever.