From the introduction:
For decades, villagers have whispered about a mysterious, benevolent figure known as the "Spirit of the Hearth" who visits during the darkest nights of winter, leaving gifts for the pure of heart. No one has ever seen him, but this year, rumors swirl that something is wrong. Strange, charred gifts have appeared at homes, fires extinguish without warning, and sightings of a dark, menacing figure clad in crimson have left villagers terrified. This being is referred to as "The Death Saint", though many dismiss him as a fearful legend.
The village mayor hires the adventurers to investigate the disappearances of children (whether this is a case of a natural beast, bandits or the Death Saint is left to the DM to decide) and a series of attacks on supply caravans. Each incident is marked by scorched earth and on the trade road there were eerie sleigh tracks that vanish into the snow.