From Introduction:
The Beast of Blackwall Canyon fits easily into any overland wilderness trek, providing a short, violent distraction for your players.
Arriving at the foot of a mighty mountain range, the last stop is a small temple to the Lady Agatha, Guardian of Travelers. The priests of the Lady Agatha organize caravans to travel through the treacherous Blackwall Canyon - the quickest and safest route through the mountain range. It is several days' journey through the narrow file and something sinister lies in it; something that preys on travelers. Large groups can usually fight off attack, but before the priests of the Lady Agatha opened their temple, few survived the journey through Blackwall Canyon. Can the party defend the caravan and make their way through the dark passage in the mountains, or will the mysterious 'Angels' of Blackwall claim yet more souls?