Descriptions, with one exception, are from the Indigo website.
Erebos by Ursula Poznanski. I've read this one. My review for it will appear on SF Signal first, then here a bit later. It was a fantastic read, and while it's marketed as YA, adult readers will enjoy it too.
When 16-year-old Nick gets a package, he wonders if it will explain the behavior of his classmates, who have been secretive lately. The package contains the mysterious computer game Erebos. Players must obey strict rules: always play alone, never talk about the game, and never tell anyone your nickname.
Curious, Nick joins the game and quickly becomes addicted. But Erebos knows a lot about the players and begins to manipulate their lives. When it sends Nick on a deadly assignment, he refuses and is banished from the game.
Now unable to play, Nick turns to a friend for help in finding out who controls the game. The two set off on a dangerous mission in which the border between reality and the virtual world begins to blur.
This utterly convincing and suspenseful thriller originated in Germany where it has become a runaway bestseller.
Girl Genius: Agatha Awakens, Omnibus 1 by Phil and Kaja Foglio
Girl Genius, the multiple Hugo Award-winning steampunk webcomic by Phil and Kaja Foglio, now collected in hardcover!
The Industrial Revolution has become all-out war! Mad Scientists, gifted with the Spark of genius, unleash insane inventions on an unprepared Europe. For centuries, the Heterodyne family of inventors kept the peace, but the last Heterodyne disappeared twenty years ago, leaving their ally Baron Klaus Wulfenbach to maintain order with his fleet of airships and army of unstoppable, if not very bright, Jaeger Monsters.
At Transylvania Polygnostic University, Agatha Clay dreams of being a scientist herself, but her trouble concentrating dooms her to be a lowly minion at best. When her locket, a family heirloom, is stolen, Agatha shows signs of having the Spark in a spectacular, destructive fashion and captures the attention of the Baron-and the Baron's handsome young son, Gilgamesh.
Swept up to the Baron's Airship City, Agatha finds herself in the midst of the greatest minds of her generation, as well as palace intrigue, dashing heroes, and an imperial cat. Agatha may be the most brilliant mind of her generation and the key to control of the continent, but first, she just has to survive.
Songs of the Earth by Elspeth Cooper
The Book of Eador, Abjurations 12:14, is very clear: Suffer ye not the life of a witch. For a thousand years, the Church Knights have obeyed that commandment, sending to the stake anyone who can hear the songs of the earth. There are no exceptions, not even for one of their own.
Novice Knight Gair can hear music no one else can, beautiful, terrible music: music with power. In the Holy City, that can mean only one thing: death by fire-until an unlikely intervention gives him a chance to flee the city and escape the flames.
With the Church Knights and their witchfinder hot on his heels, Gair hasn't time to learn how to use the power growing inside him, but if he doesn't master it, that power will tear him apart. His only hope is the secretive Guardians of the Veil, though centuries of persecution have almost destroyed their Order, and the few Guardians left have troubles of their own.
For the Veil between worlds is weakening, and behind it, the Hidden Kingdom, ever-hungry for dominion over the daylight realm, is stirring. Though he is far from ready, Gair will find himself fighting for his own life, for everyone within the Order of the Veil, and for the woman he has come to love.Quarantine: The Loners by Lex Thomas
It was just another ordinary day at McKinley High-until a massive explosion devastated the school. When loner David Thorpe tried to help his English teacher to safety, the teacher convulsed and died right in front of him. And that was just the beginning.
A year later, McKinley has descended into chaos. All the students are infected with a virus that makes them deadly to adults. The school is under military quarantine. The teachers are gone. Violent gangs have formed based on high school social cliques. Without a gang, you're as good as dead. And David has no gang. It's just him and his little brother, Will, against the whole school.
In this frighteningly dark and captivating novel, Lex Thomas locks readers inside a school where kids don't fight to be popular, they fight to stay alive.
Skylark by Meagan Spooner (synopsis from Amazon.com)
Vis in magia, in vita vi. In magic there is power, and in power, life.
For fifteen years, Lark Ainsley waited for the day when her Resource would be harvested and she would finally be an adult. After the harvest she expected a small role in the regular, orderly operation of the City within the Wall. She expected to do her part to maintain the refuge for the last survivors of the Wars. She expected to be a tiny cog in the larger clockwork of the city.
Lark did not expect to become the City's power supply.
For fifteen years, Lark Ainsley believed in a lie. Now she must escape the only world she's ever known...or face a fate more unimaginable than death.