From the introduction:
About a tenday ago, the hamlet of Spiderhaven, deep in the dark caverns of Undermountain, was set free of its merciless overlords, the drow of House Tanor’Thal. A force sent by the Lords of Waterdeep now occupies the community, planning its withdrawal to the surface within a few days.
This adventure guide adapted the commercially published Expedition to Undermountain to RPGA convention/tournament timed play. The commercial module is required to use this product. Characters are assumed to be of 4th level, and for RPGA play must conform to guidelines given in Undermountain Adventures Character Creation Guide.