Vengeance at Trollbridge

From publisher blurb: Adventure Framework 31 Vengeance at Trollbridge consists of: A downloadable, bookmarked PDF (9 A4 pages, excluding cover & credits, in both parchment and white backgrounds). The Core Adventure (Thraani, sole survivor of the Cliff Walkers barbarian clan, wants vengeance against the trolls that slew her kin! The trolls lurk in two underground complexes either side of the bridge. Can the PCs help Thraani get her revenge, and gather a few quarts of valueable trollblood while they're at it?), that will occupy 3-8 hours of session time with Minimal Prep. Rumours & Hooks suggestions.