One Foot in the Grave

I am really enjoying UF a lot right now, between this, a few Ilona Andrews series, and Charley Davidson, I must say I am on a huge UF kick, with a few YA and HR thrown in. I am trying to escape a reality(ugh). There are a few spoilers.

So, maybe someone can answer me, what makes Bones so special? He is a master vampire, but he is only 220? ish? Right? I mean, he and Cat and killed older vampires, and from what I have understood. And she did almost kill Ian. Anyways, it has been about 4 years since the events in book 1, and Bones has been looking for Cat ever since. And it seems she has been trying to forget him, unsuccessfully. Bones decides to stick around, and it becomes known there is a contract out for Cat's death.

Some really really hot sex between Bones and Cat(DUH!), and then a bunch of other stuff happens.