Based in part on the Advanced Dungeons & Dragons module Tomb of the Lizard King by Mark Acres, the HackMaster version is designed for characters level 5-7 and takes them into the village of Wayfare, the Symquoius Swamp, and finally into the titular temple.
From the back cover:
If the highwaymen who are raiding the lands of Beorn are only simple brigands, why are the merchants so terrified? And what are these rumors that are whispered among the frightened villagers -- rumors of an old, tremendously evil power that lies behind the robberies? The Count of Beorn wants your party to get to the truth.
For many years there has been peace in the lands of the Count of Beorn. The fertile plain of the river Vantress has yielded bountiful harvests, commerce has prospered, and the rule of the successive Counts of Beorn has been generally wise and good-natured, if occasionally corrupt. But of late disturbing reports of highway robbery have reached the palace at Ambigawd, the county east of Beorn. According to the tales of whimpering merchants, the sound lands are being overrun by a band of vicious brigands and the east roads are cut off by incursions of strange flying reptiles. Already there has been a complete halt to the rich trade caravans to and from Beorn's southern neighbors.
Three weeks ago the Count of Beorn sent a squad of 30 fighting men to one of the most affected areas, near the small village of Wayfare. So far there has been no report, no message, no rider -- not even a rumor of their fate. Suddenly gravely concerned, the count has called for a special group of volunteers to go to the Wayfare area, discover the fate of the first expedition, investigate reports of the brigands, and if possible to put an end to the trouble. Those who answer the call can expect danger and possibly even a horrendously painful death, but also great reward, for the count will be very grateful to those who reopen the trade routes.