What Rough Beast — Jonathan Maberry

The Gateway Project was going to save our world by opening up a doorway to infinite versions of our planet. But the threshold has gone completely out of control, sending all those other Earths onto a collision course with ours. Now, our reality is cracking apart. 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. Bewilderness: What Rough Beast continues the gripping tale of science fiction horror as two women - one human, one alien - battle each other to save infinity.