Dead to the World by Charlaine Harris

Sookie is driving home from her shift at the bar, early on New Years Day when she finds Eric the Viking vampire dressed only in jeans, running in the darkness, with know idea how he got there or who he is. To make matters worse, her brother is missing, leaving only blood and a panther track as clues. Although Eric is a master vampire with many who own fealty to him, he is lost and will only trust the woman who was brave enough to stop on the side of the road to help a man she was slightly afraid of. This is my favorite Sookie Stackhouse book to date, but without the backstory of the first three, they story wouldnt be as funny, or spellbinding.