Bonfire (Hours of the Night, #1.5)

Silent night, holy hell.

Thaddeus and Sarasija are spending the holidays on the bayou, and while the vampire's idea of Christmas cheer doesn't quite match his assistant's, they're working on a compromise. Before they can get the tree trimmed, they're interrupted by the appearance of the feu follet. The ghostly lights appear in the swamp at random and lead even the locals astray.

When the townsfolk link the phenomenon to the return of their most reclusive neighbor, suspicion falls on Thaddeus...