Witch Hunt (The Gryphonpike Chronicles Book 1)

A mute elven archer known only as Killer. Azyrin, a half Winter-orc shaman and his human swordswoman bride, Makha. Drake, the charming, swashbuckling rogue. The fireball-slinging pixie-goblin, Rahiel, and her mini-unicorn, Bill.
These are the Gryphonpike Companions.

Arriving in Strongwater Barrow, the Companions find the town riddled with plague and death. Ending the curse and saving the survivors means going into the swamps where monsters lurk and witches wait. Sounds like exactly their kind of day.

Witch Hunt is an adventure fantasy novella.

Also in the Gryphonpike Chronicles series:
Twice Drowned Dragon
A Stone's Throw
Dead of Knight
The Barrows (omnibus edition)