Shadowdark: Age of Worms (Black Water Bar)

Book 3: Encounter at Blackwall Keep

Killing the leaders of the cults of the Ebon Triad, killing the nascent Overgod, and sabotaging the route into the temples of Vecna, Hextor, and Erythnul; the party journeys to the Free City to spend their hard won coin.
At the edge of the Mistmarsh accompanied by the sage Allustan the party sees Blackwall Keep besieged by a tribe of Lizardfolk.

This is an open-table RPG West Marches campaign. Sign up and play; there's no ongoing required commitment, and the more you play, the more involved in the story your characters will be. Focus on player-driven exploration.