This adventure can be used either standalone or as a continuation of the adventure presented in The Spider Farm and The Melford Murder.
From the end note:
With the defeat of Velikul and the final clearance of the last few caverns of the dungeon, this trilogy of adventures
draws to a close. There is more than sufficient experience to be earned in these caverns for adventurers who began The Spider Farm as first level characters to reach second level, and indeed if the party is a small one with few or no henchmen, you may find that some have climbed as high as third level of experience herein.