Everneath by Brodi Ashton
Last spring, Nikki Beckett vanished, sucked into an underworld known as the Everneath, where immortals Feed on the emotions of despairing humans. Now she's returned- to her old life, her family, her friends- before being banished back to the underworld... this time forever.
I bought this right when it came out, and I haven't read it yet.
I'm thinking of making it one of my summer reads. What's getting dusty on your shelf?