I don't usually talk about the cover, but is it just me or is it ruining the theme of the previous covers? I mean the model doesn't seem very Dru-like.
Jealousy starts about a week after Betrayals. Dru has finally made it to the Schola Prima - the school she was supposed to go to and the headquarters of the Order. She's not as safe as she thought she was, Anna the only other svetocha (half vampire half human girl) seems to hate her and since she's the head of the Order - well to say the least Dru is obviously not safe there.
Now what I liked about Jealousy is that we really have a presence of an antagonist, in the other book we know that Sergej, the King of Vampires is the main villain and that he's always lurking somewhere but Anna has more of a presence since we see plenty of her in the book.
We finally see how the Order runs - we meet the council members and many new things are revealed about Elizabeth (Dru's mother) and we see her connection to Anna as well as Christophe. Things also get more heated up with Dru and Graves as well as Dru and Christophe. There's plenty of scenes for fans of either of them to enjoy. Of course we see Dibs, Shanks and Ash again.
Dru is also going through some character development, I think she's starting to trust more. Graves changes a lot too - he's not that same scared kid we saw in the first book, he's tougher - I'm sure you know what I mean if you read Betrayals.
All in all Jealousy is my favorite so far in the series, though I'll get back to you after I finished reading Defiance, the next book. Well, what else can I say? This is my second time reading through the series and it's one of my favorites and if you haven't given it a try than you're missing out!