Forgotten Realms: War of the Spider Queen #3
the group tries to find a wizard of another god to help them. He does, but betrays them and allows his god to enter and try to kill Lolth.
No real desire to read the rest of the series. I certainly won’t be buying them. The drow are jut horrible. Backstabbing, no trust, no hope. No race could have gone on like that for real. It would have imploded or torn itself apart.