The Witch of Overstrand Keep

Overstrand Keep looms, dark and abandoned, on the riverbank. Within it lurks a crafty witch, amassing magical items which she consumes to extend her life. 

In this story kit for the Grimwild TTRPG, your players are tasked with recovering one or more magic items from the keep and escaping with their lives. It is flexible enough to run as a gritty dungeon-crawl or a thrilling heist. Will the heroes brave the dangers of the castle and come out on top? Or will they fall to the witch's wrath and be engulfed as the keep sinks into the mire?