You're in the weird looking place? IIRC, there should be an exit somewhere along the south end of the map. It brings you back up to the first level below the Temple Sewers (the corridor that leads from the lich's tomb).
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"Butt-kicking for goodness!" - Minsc
"Cities always teem with evil and decay. Let's give it a good shake and SEE WHAT FALLS OUT!!" - Minsc
