This fourth book of the Southern Vampire Series, is where I fell inlove with the character Eric Northman. Sookie and Bill have broken up, and on her way home from work, Sookie sees a naked man running. The naked man turns out to be none other than the vampire Eric. When Sookie sees that it is Eric, she stops to help him, and here's the interesting part, Eric has no idea who he is, or how he got there.
Sookie phones Pam, Eric's second in command, and explains the state that Eric is in, and Pam explains how that has come to be. Sookie is asked to look after Eric, whilst he is in that state since the vampires have a problem with some rogue witches. It all gets very interesting and culminates in a witch war - with the vampires and weres fighting together.
But whilst Eric is in this altered state of mind, he becomes endearing and it would seem that Sookie falls in love with him. This new Eric who is so unlike the hardened Eric that she knows. When Eric gets his memory back he recalls nothing of their time together.
If you only read one Southern Vampire book - let this be it.