Blood Moon Rising

From the first page:

"Twice a year in the skies over Sommerlund, Ishir’s face turns a deep, brooding red. These nights, the five long nights of the Blood Moon, are rumoured to be when terrible
beasts walk the face of Magnamund. The wise remain indoors waiting for Kai’s light to banish the monsters once more. Those caught outside during the Blood Moon are often never seen again."