Bewilderness - Jonathan Maberry

Bewilderness is a gripping tale of science fiction horror as two women-one human, one alien-battle each other to save infinity.

Dr. Abby Corman has a bold idea: open a stable doorway between our world and an uninhabited parallel Earth. A new world we can use to mine resources to end poverty, grow enough food to end all hunger, and allow for population growth to end overcrowding. What could be a more noble aspiration for a brilliant young scientist?

But the path to hell is paved with good intentions...

The Gateway is in a secure lab in a huge office building in New York. Ultra-modern, totally secure, impenetrable by industrial spies or foreign agents. Once it goes into lockdown for the Gateway test firing, it becomes the world's largest and most unbreakable vault. 

Locked doors, though, can do more than keep bad things out. They can trap bad things in.

The Gateway spins completely out of control, sending infinite Earths onto a collision course with ours. Now, our reality is cracking apart, allowing creatures from Earth's distant past and monsters from parallel worlds to emerge, turning New York into a hellscape.

Abby Corman did not open the Gateway, but she is the only one who knows how to close it. But an alien Hunter and her pack of deadly hellcats have stepped into our world, and they will stop at nothing to kill Abby. Because in a universe of parallel worlds, one Earth's savior can be the worst criminal other Earths have ever known.