The main focus of Envy is on the relationship between Penelope, Henry, and Diana. Lina and Elizabeth still have a role to play, but it's not quite as important.
A good amount of the plot in this one revolves around Henry trying to get out of his marriage, while Penelope tries to make him stay. It becomes this dance between the two of them, with Penelope doing something to make it impossible for Henry to leave her, and then Henry finding a way to leave Penelope that would make her look bad if she tried to blackmail him again. Lather. Rinse. Repeat.
It was pretty entertaining to watch. Especially their last moves against each other. I can't wait to see what ends up happening with both of their decisions.
For Lina's part, she falls in love, loses everything, and then gets everything back again.
And Elizabeth...well, it's pretty obvious. It's exactly the plot twist you'd expect to happen to her. I'm waiting to see if my prediction for Snowden's part in everything is correct. Given how predictable this series has been so far, I've got faith that what I imagine happening is right. Prediction: Snowden arranged to have the police find Elizabeth and Will trying to get on the train - he was the one who told them that New Year's Day would be a quiet day to travel, which it clearly wasn't. Then, after he and Elizabeth got married, she told him that she still thought of herself as Mrs. Keller, but his final line in the book was to call her Mrs. Cairns. Which, I mean, technically she is, and that's what she should be called in public. But he called her that right after their talk about how she still thinks of herself as Will's wife. I'll leave this here, even if I turn out to be wrong - it was part of my reading experience, after all.
Again, the ending of the book is much better than the rest of it. They're definitely the strongest parts of the story. This one isn't as depressing as the previous two...it ends on a more hopeful note. But it was still cool.
I'll just say this. If Diana's plan doesn't work, I'm going to be bored with the next book.